Journal: Heart Rhythm

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Abstract

Infectious consequences of hematoma from cardiac implantable electronic device procedures and the role of the antibiotic envelope: A WRAP-IT Trial Analysis.

Tarakji KG, Korantzopoulos P, Philippon F, Biffi M, ... Seshadri S, Wilkoff BL
Background
Hematoma is a complication of cardiac implantable electronic device (CIED) procedures and may lead to device infection. The TYRX antibacterial envelope reduced major CIED infection by 40% in the randomized WRAP-IT trial, but its effectiveness in the presence of hematoma is not well understood.
Objective
Evaluate the incidence and infectious consequences of hematoma and the association between envelope use, hematomas, and major CIED infection among WRAP-IT patients.
Methods
All 6800 study patients were included in this analysis (control = 3429; envelope = 3371). Hematomas occurring within 30 days post-procedure (acute) were characterized and grouped by study treatment and evaluated for subsequent infection risk. Data were analyzed using Cox proportional hazard regression modeling.
Results
Acute hematoma incidence was 2.2% at 30 days and there was no significant difference between treatment groups (envelope vs. control HR: 1.15, 95% CI: 0.84-1.58, p = 0.39). Through all follow-up, the risk of major infection was significantly higher among control patients with hematoma vs those without (13.1% vs. 1.6%; HR: 11.3, 95%CI: 5.5-23.2, p < 0.001). The risk of major infection was significantly lower in the envelope vs control patients with hematoma (2.5% vs. 13.1%; HR: 0.18, 95%CI 0.04-0.85, p = 0.03).
Conclusion
The risk of hematoma was 2.2% among the WRAP-IT trial patients. Among control patients, hematoma carried >11-fold risk of developing a major CIED infection. This risk was significantly mitigated with antibacterial envelope use as there was an 82% reduction in major CIED infection among envelope patients who developed hematoma compared to control.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 15 Jul 2021; epub ahead of print
Tarakji KG, Korantzopoulos P, Philippon F, Biffi M, ... Seshadri S, Wilkoff BL
Heart Rhythm: 15 Jul 2021; epub ahead of print | PMID: 34280568
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Abstract

Impact of specialized electrophysiological care on outcome of catheter ablation for supraventricular tachycardias in adults with congenital heart disease: Independent risk factors and gender aspects.

Fischer AJ, Enders D, Wasmer K, Marschall U, Baumgartner H, Diller GP
Background
Limited data exist on the impact of gender and specialized care on the requirement of repeat treatment of supraventricular tachycardia (SVT) in adult patients with congenital heart disease (ACHD).
Objective
The study aimed to assess independent predictors for a combined endpoint of re-CA or cardioversion at 3 years of follow-up including the impact of gender and specialized ACHD care.
Methods
All ACHD registered at a database of one of the largest German Health Insurers (≈9.2 million members) who underwent catheter ablation (CA) for SVT were analyzed.
Results
Of 38,892 ACHD ≥16 years, 485 (49.5% women, median age 58.4 years) underwent CA for SVT. Over the three-year follow-up, the number of yearly CA increased significantly particularly for treatment of atrial fibrillation (AF) (+195%) and atrial flutter (+108%). Moderate to severe complexity heart disease (Odds ratio [OR] 1.66; p=0.01), advanced age (OR 1.85 per year; p=0.02), chronic kidney disease (OR 1.70; p=0.01) and AF (OR 2.02; p=0.002) emerged as independent predictors for re-treatment. Re-treatment was significantly less often performed if the primary CA was carried out at a specialized ACHD center (p=0.009) in patients with moderate to severe complexity. Women treated at specialist centers had a 1.6-fold reduced risk of undergoing re-treatment (p=0.01).
Conclusion
CA for SVT is increasingly performed in ACHD, especially for atrial flutter and atrial fibrillation. Patients with moderate and severe complexity congenital heart defects and female ACHD benefit from upfront referral to specialized ACHD centers for CA. Centralization of care for ACHD arrhythmias should thus be advocated.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 12 Jul 2021; epub ahead of print
Fischer AJ, Enders D, Wasmer K, Marschall U, Baumgartner H, Diller GP
Heart Rhythm: 12 Jul 2021; epub ahead of print | PMID: 34271174
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Abstract

Long term complications in patients implanted with subcutaneous implantable defibrillators Real-world data from the Extended ELISIR experience.

Gasperetti A, Schiavone M, Ziacchi M, Vogler J, ... Forleo G, Biffi M
Background
Recently, the Food and Drug administration issued a recall for the subcutaneous implantable cardioverter defibrillator (S-ICD) due to the possibility of lead ruptures and accelerated battery depletion.
Objective
Aim of this study is to evaluate device-related complications over time in a real-world multicentered large S-ICD cohort.
Methods
Patients implanted with S-ICD from January 2015 to June 2020 were enrolled from a 19 institution European registry (ELISIR NCT0473876). Device-related complication rates over follow-up were collected. Last follow-up of patients was performed after the Boston Scientific recall issue.
Results
A total of 1254 patients (52.0 [41.0-62.2] years, 77.6% male, 30.9% ischemic) was enrolled. Over a follow-up of 23.2 [12.8-37.8] months, complications were observed in 117 (9.3%) patients, for a total of 127 device-related complications (23.6% managed conservatively, 76.4%) requiring reintervention). Twenty-seven (2.2%) patients had an unanticipated generator replacement, after 3.6 [3.3-3.9] years, while 4 (0.3%) had a lead rupture. BMI (HR 1.063 [1.028-1.100]; p=0.000), chronic kidney disease (HR 1.960 [1.191-3.225]; p=0.008), and oral anticoagulation (HR 1.437 [1.010-2.045]; p=0.043) were associated with an increase of overall complications whereas older age (HR 0.980 [0.967-0.994]; p=0.007) and procedure performed in high volume centers (HR 0.463 [0.300-0.715]; p=0.001) were protective factors.
Conclusion
The overall complication rate over 23.2 months of follow-up in a multicentered S-ICD cohort was 9.3%. Early unanticipated device battery depletions occurred in 2.2% of patients, while lead fracture was observed in 0.3%, in line with the expected rates reported from Boston Scientific.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 12 Jul 2021; epub ahead of print
Gasperetti A, Schiavone M, Ziacchi M, Vogler J, ... Forleo G, Biffi M
Heart Rhythm: 12 Jul 2021; epub ahead of print | PMID: 34271173
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Abstract

Sex differences in the origin of Purkinje ectopy initiating idiopathic ventricular fibrillation.

Surget E, Cheniti G, Ramirez FD, Leenhardt A, ... Hocini M, Haïssaguerre M
Background
Purkinje ectopics (PurkE) are major triggers of idiopathic ventricular fibrillation (VF). Identifying clinical factors associated with specific PurkE characteristics could yield insights into the mechanisms of Purkinje-mediated arrhythmogenicity.
Objective
To examine the associations of clinical, environmental, and genetic factors with PurkE origin in patients with PurkE-initiated idiopathic VF.
Methods
Consecutive patients from four arrhythmia referral centers with PurkE-initiated idiopathic VF were included. We evaluated demographics, medical history and clinical circumstances associated with index VF events, and electrophysiologic characteristics of PurkE. An electrophysiological study was performed in most patients to confirm the Purkinje origin.
Results
Eighty three patients were included (age 38 ± 14 years, 44 women) among whom 32 had a previous history of syncope. Fourty four patients had VF at rest. PurkE originated from the right ventricle (RV) in 41 cases (49%), from the left ventricle (LV) in 36 (44%) and from the both ventricles in 6 (7%). Seasonal and circadian distributions of VF episodes were similar according to PurkE origin. Clinical characteristics of patients with RV vs. LV PurkE origins were similar except for sex. RV PurkE were more frequent in men than women (76% vs 24%) whereas LV and biventricular PurkE were more frequent in women (81% vs 19% and 83% vs 17% respectively, p<0.0001).
Conclusion
PurkE triggering idiopathic VF originate dominantly from RV in men and from LV or both ventricles in women adding to other sex-related arrhythmias as Brugada syndrome or long QT. Sex-based factors influencing Purkinje arrhythmogenicity warrant investigation.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 10 Jul 2021; epub ahead of print
Surget E, Cheniti G, Ramirez FD, Leenhardt A, ... Hocini M, Haïssaguerre M
Heart Rhythm: 10 Jul 2021; epub ahead of print | PMID: 34260987
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Abstract

Identification of a SCN5A Founder Mutation Causing Sudden Death, Brugada Syndrome and Conduction Blocks in Southern Italy.

Curcio A, Malovini A, Mazzanti A, Memmi M, ... Bellazzi R, Napolitano C
Background
The genetic architecture of Brugada syndrome (BrS) is emerging as an increasingly complex area of investigation. The identification of genetically homogeneous populations can provide mechanistic insights and improve genotype-phenotype correlation.
Objective
To characterize and define the clinical implications of a novel BrS founder mutation. Using a haplotype-based approach we investigated whether two SCN5A genetic variants could derive from founder events.
Methods
Single nucleotide polymorphisms were genotyped in 201 subjects, haplotypes reconstructed and mutational age estimated. Clinical phenotypes and historical records were collected.
Results
A SCN5A variant (c.3352C>T; p.Gln1118Ter) was identified in 3 probands with BrS originating from South Italy. The same mutation was identified in a proband from central Italy and in one U.S. resident subject with Italian ancestry. The five individuals carried a common core haplotype, whose frequency was extremely low in local non-carrier probands and in population controls (0%-6.06%). The clinical presentation included multi-generational dominant transmission of Brugada electrocardiographic pattern, high incidence of sudden cardiac death (SCD) and cardiac conduction defects (CCD). We reconstructed seven-generation pedigrees with common geographic origin. Variant\'s age estimates suggested that origin of the p.Gln1118Ter dates back 76 generations (95% Confidence Interval: 28-200). A second SCN5A variant (c.5350G>A; p.Glu1784Lys) identified in the region did not show similar founder signal.
Conclusions
p.Gln1118Ter is a novel BrS/CCD/SCD founder mutation. We illustrate how these findings provide insights on the inheritance patterns and phenotypes associated with SCN5A mutation.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 06 Jul 2021; epub ahead of print
Curcio A, Malovini A, Mazzanti A, Memmi M, ... Bellazzi R, Napolitano C
Heart Rhythm: 06 Jul 2021; epub ahead of print | PMID: 34245912
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Abstract

Epicardial Course of the Musculature Related to the Great Cardiac Vein: Anatomical Considerations and Clinical Implications for Mitral Isthmus Block after Vein of Marshall Ethanol Infusion.

Pambrun T, Derval N, Duchateau J, Denis A, ... Haïssaguerre M, Jaïs P
Background
Mitral isthmus gaps have been ascribed to an epicardial musculature anatomically related to the great cardiac vein (GCV) and the vein of Marshall (VOM). Their lumen offers an access for radiofrequency application or ethanol infusion, respectively.
Objective
To evaluate the frequency of mitral isthmus gaps accessible via the GCV lumen, to assess their location around the GCV circumference, and to propose an efficient ablation strategy when present.
Methods
One hundred consecutive patients underwent VOM ethanol infusion (step 1) and endocardial linear ablation from the mitral annulus to the left inferior pulmonary vein (step 2). In cases of mitral isthmus gap, endovascular ablation of the GCV anchored wall facing the left atrium was systematically performed (step 3), while the opposite GCV free wall was targeted in case of block failure only (step 4).
Results
After VOM ethanol infusion and endocardial ablation, mitral isthmus block occurred in 51 patients (51%). Pacing maneuvers and activation sequences demonstrated an epicardial gap via the VOM in 2 patients (2%), and via the GCV in 47 patients (47%). In the latter case, block was achieved at the GCV anchored wall in 42 patients (89%), and the GCV free wall in 5 patients (11%). Global success rate of mitral isthmus block was 98%. No tamponade occurred.
Conclusion
With the advent of VOM ethanol infusion, residual mitral isthmus gaps are mostly eliminated within the first centimeter of the GCV. Thorough mapping of the entire circumference of the GCV wall can help identify these epicardial gaps.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 30 Jun 2021; epub ahead of print
Pambrun T, Derval N, Duchateau J, Denis A, ... Haïssaguerre M, Jaïs P
Heart Rhythm: 30 Jun 2021; epub ahead of print | PMID: 34217842
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Abstract

Determinants of outcome impact of vein of Marshall ethanol infusion when added to catheter ablation of persistent atrial fibrillation: A secondary analysis of the VENUS randomized clinical trial.

Lador A, Peterson LE, Swarup V, Schurmann PA, ... Kleiman NS, Valderrábano M
Background
The Vein of Marshall Ethanol for Untreated Persistent AF (VENUS) trial demonstrated that adding vein of Marshall (VOM) ethanol infusion to catheter ablation (CA) improves ablation outcomes in persistent atrial fibrillation (AF). There was significant heterogeneity in the impact of VOM ethanol infusion on rhythm control.
Objective
The purpose of this study was to assess the association between outcomes and (1) achievement of bidirectional perimitral conduction block and (2) procedural volume.
Methods
The VENUS trial randomized patients with persistent AF (N = 343) to CA combined with VOM ethanol or CA alone. The primary outcome (freedom from AF or atrial tachycardia [AT] lasting longer than 30 seconds after a single procedure) was analyzed by 2 categories: (1) successful vs no perimitral block and (2) high- (>20 patients enrolled) vs low-volume centers.
Results
In patients with perimitral block, the primary outcome was reached 54.3% after VOM-CA and 37% after CA alone (P = .01). Among patients without perimitral block, freedom from AF/AT was 34.0% after VOM-CA and 37.0% after CA (P = .583). In high-volume centers, the primary outcome was reached in 56.4% after VOM-CA and 40.2% after CA (P = .01). In low-volume centers, freedom from AF/AT was 30.77% after VOM-CA and 32.61% after CA (P = .84). In patients with successful perimitral block from high-volume centers, the primary outcome was reached in 59% after VOM-CA and 39.1% after CA (P = .01). Tests for interaction were significant (P = .002 for perimitral block and P = .04 for center volume).
Conclusion
Adding VOM ethanol infusion to CA has a greater impact on outcomes when associated with perimitral block and performed in high-volume centers. Perimitral block should be part of the VOM procedure.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1045-1054
Lador A, Peterson LE, Swarup V, Schurmann PA, ... Kleiman NS, Valderrábano M
Heart Rhythm: 29 Jun 2021; 18:1045-1054 | PMID: 33482387
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Abstract

Arrhythmias and device therapies in patients with cancer therapy-induced cardiomyopathy.

Lee C, Maan A, Singh JP, Fradley MG
Our knowledge of associated cardiotoxicities from novel therapeutics in oncology continues to expand. These include arrhythmias from cancer-therapy induced cardiomyopathy resulting from both direct and indirect effects on cardiomyocytes and other mechanisms that can adversely impact cardiovascular outcomes and overall mortality. In this review, we focus on both the arrhythmias of various classes of oncologic agents as well as the use of cardiac implantable electronic devices (cardioverter-defibrillators, permanent pacemakers, and cardiac resynchronization therapy) in cardio-oncology patients.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1223-1229
Lee C, Maan A, Singh JP, Fradley MG
Heart Rhythm: 29 Jun 2021; 18:1223-1229 | PMID: 33640446
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Abstract

Major adverse clinical events associated with implantation of a leadless intracardiac pacemaker.

Hauser RG, Gornick CC, Abdelhadi RH, Tang CY, Casey SA, Sengupta JD
Background
Leadless intracardiac pacemakers were developed to avoid the complications of transvenous pacing systems. The Medtronic Micra™ transcatheter pacemaker is one such system. We found an unexpected number of major adverse clinical events (MACE) in the Food and Drug Administration\'s Manufacturers and User Facility Device Experience (MAUDE) database associated with Micra implantation.
Objective
The purpose of this study was to describe these MACE and compare them to implant procedure MACE in MAUDE for Medtronic CapSureFix™ active-fixation transvenous pacing leads.
Methods
During January 2021, we queried the MAUDE database for reports of MACE for Micra pacemakers and CapSureFix leads using the simple search terms \"death,\" \"tamponade,\" and \"perforation.\" Reports from 2016-2020 were included.
Results
The search identified 363 MACE for Micra and 960 MACE for CapSureFix leads, including 96 Micra deaths (26.4%) vs 23 CapSureFix deaths (2.4%) (P <.001); 287 Micra tamponades (79.1%) vs 225 tamponades for CapSureFix (23.4%) (P <.001); and 99 rescue thoracotomies for Micra (27.3%) vs 50 rescue thoracotomies for CapSureFix (5.2%) (P <.001). More Micra patients required cardiopulmonary resuscitation (21.8% vs 1.1%) and suffered hypotension or shock (22.0% vs 5.8%) than CapSureFix recipients (P <.001). Micra patients were more likely to survive a myocardial perforation or tear if they had surgical repair (P = .014).
Conclusion
Micra leadless pacemaker implantation may be complicated by myocardial and vascular perforations and tears that result in cardiac tamponade and death. We estimate the incidence is low (<1%). Rescue surgery to repair perforations may be lifesaving. MACE are significantly less for implantation of CapSureFix transvenous ventricular pacing leads.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1132-1139
Hauser RG, Gornick CC, Abdelhadi RH, Tang CY, Casey SA, Sengupta JD
Heart Rhythm: 29 Jun 2021; 18:1132-1139 | PMID: 33713856
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Abstract

Comparison of the effect of glucose-lowering agents on the risk of atrial fibrillation: A network meta-analysis.

Shi W, Zhang W, Zhang D, Ren G, ... Chen H, Ding C
Background
Diabetes is associated with the progression of atrial fibrillation (AF) and atrial flutter (AFL). However, whether glucose-lowering agents could reduce AF/AFL remains unclear. We hypothesized that different glucose-lowering agents exhibit different characteristic effects on the risk of AF/AFL.
Objectives
The goals of this study were to evaluate the effect of different glucose-lowering agents and identify the optimal treatment that can reduce AF/AFL events in patients with diabetes.
Methods
We searched PubMed, Embase, and the Cochrane Library from their inception to September 30, 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used in this network meta-analysis. The primary end point of our study was AF or AFL. Only studies that reported AF/AFL as clinical end points with a follow-up period of at least 12 months were included. The results from trials were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The results were pooled using a Bayesian random-effects model.
Results
Five eligible studies (9 glucose-lowering agents, including thiazolidinedione, metformin, sulfonylurea, insulin, dipeptidyl peptidase-4 inhibitor, glucagon-like peptide-1 receptor agonist [GLP-1RA], sodium-glucose cotransporter 2 inhibitor, alpha-glucosidase inhibitor, and non-sulfonylurea) consisting of 263,583 patients with type 2 diabetes mellitus were included. Based on the pooled results, GLP-1RA significantly reduced AF/AFL events compared with metformin (OR 0.17; 95% CI 0.04-0.61), sulfonylurea (OR 0.23; 95% CI 0.07-0.73), insulin (OR 0.20; 95% CI 0.07-0.86), and non-sulfonylurea (OR 0.18; 95% CI 0.04-0.66).
Conclusion
Compared with other glucose-lowering agents, GLP-1RA could reduce the risk of AF/AFL in patients with diabetes.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 29 Jun 2021; 18:1090-1096
Shi W, Zhang W, Zhang D, Ren G, ... Chen H, Ding C
Heart Rhythm: 29 Jun 2021; 18:1090-1096 | PMID: 33684547
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Abstract

Skin sympathetic nerve activity as a biomarker for neurologic recovery during therapeutic hypothermia for cardiac arrest.

Kutkut I, Uceda D, Kumar A, Wong J, ... Chen PS, Everett TH
Background
Targeted temperature management (TTM) improves neurologic outcome after cardiac arrest. However, better neurologic prognostication is needed.
Objective
The purpose of this study was to test the hypothesis that noninvasive recording of skin sympathetic nerve activity (SKNA) and its association with heart rate (HR) during TTM may serve as a biomarker of neurologic status.
Methods
SKNA recordings were analyzed from 29 patients undergoing TTM. Patients were grouped based on Clinical Performance Category (CPC) score into group 1 (CPC 1-2) representing a good neurologic outcome and group 2 (CPC 3-5) representing a poor neurologic outcome.
Results
Of the 29 study participants, 18 (62%) were deemed to have poor neurologic outcome. At all timepoints, low average skin sympathetic nerve activity (aSKNA) was associated with poor neurologic outcome (odds ratio 22.69; P = .002) and remained significant (P = .03) even when adjusting for presenting clinical factors. The changes in aSKNA and HR during warming in group 1 were significantly correlated (ρ = 0.49; P <.001), even when adjusting for corresponding temperature and mean arterial pressure measurements (P = .017), whereas this correlation was not observed in group 2. Corresponding to high aSKNA, there was increased nerve burst activity during warming in group 1 compared to group 2 (0.739 ± 0.451 vs 0.176 ± 0.231; P = .013).
Conclusion
Neurologic recovery was retrospectively associated with SKNA. Patients undergoing TTM who did not achieve neurologic recovery were associated with low SKNA and lacked a significant correlation between SKNA and HR. These preliminary results indicate that SKNA may potentially be a useful biomarker to predict neurologic status in patients undergoing TTM.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1162-1170
Kutkut I, Uceda D, Kumar A, Wong J, ... Chen PS, Everett TH
Heart Rhythm: 29 Jun 2021; 18:1162-1170 | PMID: 33689908
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Abstract

Percentage of age-predicted cardiorespiratory fitness and risk of sudden cardiac death: A prospective cohort study.

Laukkanen JA, Kurl S, Khan H, Kunutsor SK
Background
The inverse associations between cardiorespiratory fitness (CRF) and vascular outcomes have been established. However, there has been no prospective evaluation of the relationship between percentage of age-predicted cardiorespiratory fitness (%age-predicted CRF) and risk of sudden cardiac death (SCD).
Objective
The purpose of this study was to assess the association of %age-predicted CRF with SCD risk in a long-term prospective cohort study.
Methods
CRF was assessed using the gold standard respiratory gas exchange analyzer in 2276 men who underwent cardiopulmonary exercise testing. The age-predicted CRF estimated from a regression equation for age was converted to %age-predicted CRF using (Achieved CRF/Age-predicted CRF) × 100. Hazard ratios (HRs) [95% confidence intervals (CIs)] were calculated for SCD.
Results
During median follow-up of 28.2 years, 260 SCDs occurred. There was a dose-response relationship between age-predicted CRF and SCD. A 1-SD increase in %age-predicted CRF was associated with a decreased risk of SCD in analysis adjusted for established risk factors (HR 0.60; 95% CI 0.53-0.70), which remained consistent on further adjustment for several potential confounders, including alcohol consumption, physical activity, socioeconomic status, and systemic inflammation (HR 0.73; 95% CI 0.62-0.85). The corresponding adjusted HRs were 0.34 (0.23-0.50) and 0.52 (0.34-0.79), respectively, when comparing extreme quartiles of %age-predicted CRF levels. HRs for the associations of absolute CRF levels with SCD risk in the same participants were similar.
Conclusion
Percentage of age-predicted CRF is continuously, strongly, and independently associated with risk of SCD and is comparable to absolute CRF as a risk indicator for SCD.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1171-1177
Laukkanen JA, Kurl S, Khan H, Kunutsor SK
Heart Rhythm: 29 Jun 2021; 18:1171-1177 | PMID: 33689907
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Impact:
Abstract

Gender-affirming hormone treatment causes changes in gender phenotype in a 12-lead electrocardiogram.

Saito N, Nagahara D, Ichihara K, Masumori N, Miura T, Takahashi S
Background
Men and women have specific patterns in an electrocardiogram (ECG) differentiated by J-point elevation and ST-segment angle. Although gender-affirming hormone treatment is one of the treatments for gender dysphoria, its influence on an ECG has not been clarified yet.
Objective
The purpose of this study was to investigate ECG changes induced by gender-affirming hormone treatment.
Methods
The study population consisted of 29 transgender males and 8 transgender females and 37 age- and sex-matched cisgender females and males. Male pattern was defined as J-point elevation > 0.1 mV and ST-segment angle > 20° in precordial leads.
Results
In the comparison between 29 transgender males and cisgender females, the prevalence of the male pattern (89.7% vs 6.9%; P < .001), prevalence of the early repolarization pattern (51.7% vs 17.2%; P = .01), J-point elevation (leads V1-V6), T-wave amplitudes (leads V1-V6), QRS amplitudes (leads II, III, V1-V6), and P-wave amplitudes (leads V1-V3) were significantly higher in transgender males. The prevalence of the male pattern was lower in transgender females than in cisgender males (25.0% vs 87.5%; P = .04). In the analysis of transgender males for whom ECGs were available before and after gender-affirming hormone treatment (n = 13), J-point elevation and T-wave amplitudes significantly increased after gender-affirming hormone treatment, leading to a higher prevalence of the male pattern (23.1% vs 92.3%; P < .001). The prevalence of the early repolarization pattern and QRS amplitudes also significantly increased after the treatment, but the augmentation of P-wave amplitudes was modest.
Conclusion
Gender-affirming hormone treatment for gender dysphoria is accompanied by a change in ECG phenotype toward affirming gender, in which change in androgen level may be involved.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1203-1209
Saito N, Nagahara D, Ichihara K, Masumori N, Miura T, Takahashi S
Heart Rhythm: 29 Jun 2021; 18:1203-1209 | PMID: 33706005
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Abstract

Arrhythmia-induced cardiomyopathy: A potentially reversible cause of refractory cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation.

Hékimian G, Paulo N, Waintraub X, Bréchot N, ... Gandjbakhch E, Luyt CE
Background
The most severe form of arrhythmia-induced cardiomyopathy in adults- refractory cardiogenic shock requiring mechanical circulatory support-has rarely been reported.
Objective
The purpose of this study was to describe the management of critically ill patients admitted for acute, nonischemic, or worsening of previously known cardiac dysfunction and recent-onset supraventricular arrhythmia who developed refractory cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO).
Methods
This study is a retrospective analysis of prospectively collected data.
Results
Between 2004 and 2018, 35 patients received VA-ECMO for acute, nonischemic cardiogenic shock and recent supraventricular arrhythmia (77% atrial fibrillation [AF]). Cardiogenic shock was the first disease manifestation in 21 patients (60%). Characteristics at ECMO implantation [median (interquartile range)] were Sequential Organ Failure Assessment score 10 (7-13); inotrope score 29 (11-80); left ventricular ejection (LVEF) fraction 10% (10%-15%); and lactate level 8 (4-11) mmol/L. For 12 patients, amiodarone and/or electric cardioversion successfully reduced arrhythmia, improved LVEF, and enabled weaning off VA-ECMO; 11 had long-term survival without transplantation or long-term assist device. Eight patients experiencing arrhythmia-reduction failure underwent ablation procedures (7 atrioventricular node [AVN] with pacing, 1 atrial tachycardia) and were weaned off VA-ECMO; 7 survived. Of the remaining 15 patients without arrhythmia reduction or ablation, only the 6 bridged to heart transplantation or left ventricular (LV) assist device survived.
Conclusion
Arrhythmia-induced cardiomyopathy, mainly AF-related, is an underrecognized cause of refractory cardiogenic shock and should be considered in patients with nonischemic cardiogenic shock and recent-onset supraventricular arrhythmia. VA-ECMO support allowed safe arrhythmia reduction or rate control by AVN ablation while awaiting recovery, even among those with severe LV dilation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1106-1112
Hékimian G, Paulo N, Waintraub X, Bréchot N, ... Gandjbakhch E, Luyt CE
Heart Rhythm: 29 Jun 2021; 18:1106-1112 | PMID: 33722763
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Abstract

Effect of preload reducing therapy on right ventricular size and function in patients with arrhythmogenic right ventricular cardiomyopathy.

Kalantarian S, Vittinghoff E, Klein L, Scheinman MM
Background
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of sudden cardiac death in young people and athletes. To date, no treatment has proven to slow the progression of the disease. Preload reducing agents such as nitrates and diuretics have shown promising results in preventing training-induced development of ARVC in a murine model.
Objective
The purpose of this study was to describe our experience with preload reducing therapy in patients with ARVC and symptomatic right ventricular (RV) dysfunction.
Methods
We performed retrospective chart review of prospectively collected registry data and included 20 patients with definite ARVC who had serial echocardiographic measurements and an implantable cardioverter-defibrillator. Six of the 20 patients with RV end-diastolic area (RVEDA) above median (>25 cm2) and New York Heart Association functional class II-IV symptoms were successfully treated with long-term isosorbide dinitrate 5-40 mg tid (at maximum tolerated dose) and hydrochlorothiazide-spironolactone 25-25 mg daily. The main outcomes of interest were RVEDA, RV fractional area change (FAC), and RV outflow tract measurements. Generalized estimating equations with repeated measures were used to identify the association between preload reducing agents and echocardiographic structural progression.
Results
Patients who received preload reducing agents (n = 6) were older and had larger RVs with lower FAC at baseline. However, treatment with preload reducing agents was associated with less RVEDA enlargement during mean 3.3 (range 1-6.7) years of treatment in multivariate analysis (% change in RVEDA associated with treatment -7.71; 95% confidence interval -13.29 to -2.13; P = .007).
Conclusion
Preload reducing agents show promising results in slowing RV enlargement in patients with ARVC and show possible disease-modifying potential.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1186-1191
Kalantarian S, Vittinghoff E, Klein L, Scheinman MM
Heart Rhythm: 29 Jun 2021; 18:1186-1191 | PMID: 33722762
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Impact:
Abstract

Effect of ivabradine on cardiac arrhythmias: Antiarrhythmic or proarrhythmic?

Marciszek M, Paterek A, Oknińska M, Zambrowska Z, Mackiewicz U, Mączewski M
Cardiac arrhythmias are a major source of mortality and morbidity. Unfortunately, their treatment remains suboptimal. Major classes of antiarrhythmic drugs pose a significant risk of proarrhythmia, and their side effects often outweigh their benefits. Therefore, implantable devices remain the only truly effective antiarrhythmic therapy, and new strategies of antiarrhythmic treatment are required. Ivabradine is a selective heart rate-reducing agent, an inhibitor of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, currently approved for treatment of coronary artery disease and chronic heart failure. In this review, we focus on the clinical and basic science evidence for the antiarrhythmic and proarrhythmic effects of ivabradine. We attempt to dissect the mechanisms behind the effects of ivabradine and indicate the focus of future studies.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1230-1238
Marciszek M, Paterek A, Oknińska M, Zambrowska Z, Mackiewicz U, Mączewski M
Heart Rhythm: 29 Jun 2021; 18:1230-1238 | PMID: 33737235
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Impact:
Abstract

Atrial resting membrane potential confers sodium current sensitivity to propafenone, flecainide and dronedarone.

Holmes AP, Saxena P, Kabir SN, O\'Shea C, ... Fabritz L, Kirchhof P
Background
Although atrial fibrillation ablation is increasingly used for rhythm control therapy, antiarrhythmic drugs (AADs) are commonly used, either alone or in combination with ablation. The effectiveness of AADs is highly variable. Previous work from our group suggests that alterations in atrial resting membrane potential (RMP) induced by low Pitx2 expression could explain the variable effect of flecainide.
Objective
The purpose of this study was to assess whether alterations in atrial/cardiac RMP modify the effectiveness of multiple clinically used AADs.
Methods
The sodium channel blocking effects of propafenone (300 nM, 1 μM), flecainide (1 μM), and dronedarone (5 μM, 10 μM) were measured in human stem cell-derived cardiac myocytes, HEK293 expressing human NaV1.5, primary murine atrial cardiac myocytes, and murine hearts with reduced Pitx2c.
Results
A more positive atrial RMP delayed INa recovery, slowed channel inactivation, and decreased peak action potential (AP) upstroke velocity. All 3 AADs displayed enhanced sodium channel block at more positive atrial RMPs. Dronedarone was the most sensitive to changes in atrial RMP. Dronedarone caused greater reductions in AP amplitude and peak AP upstroke velocity at more positive RMPs. Dronedarone evoked greater prolongation of the atrial effective refractory period and postrepolarization refractoriness in murine Langendorff-perfused Pitx2c+/- hearts, which have a more positive RMP compared to wild type.
Conclusion
Atrial RMP modifies the effectiveness of several clinically used AADs. Dronedarone is more sensitive to changes in atrial RMP than flecainide or propafenone. Identifying and modifying atrial RMP may offer a novel approach to enhancing the effectiveness of AADs or personalizing AAD selection.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1212-1220
Holmes AP, Saxena P, Kabir SN, O'Shea C, ... Fabritz L, Kirchhof P
Heart Rhythm: 29 Jun 2021; 18:1212-1220 | PMID: 33737232
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Impact:
Abstract

Fasciculoventricular and atrioventricular accessory pathways in patients with Danon disease and preexcitation: A multicenter experience.

Darden D, Hsu JC, Tzou WS, von Alvensleben JC, ... Feld GK, Adler E
Background
Studies have suggested that a fasciculoventricular pathway (FVP) may be the cause of preexcitation in patients with Danon disease, a rare X-linked dominant genetic disorder of hypertrophic cardiomyopathy.
Objective
The purpose of this study was to describe the prevalence of ventricular preexcitation on resting 12-lead electrocardiogram (ECG) in patients with Danon disease and the electrophysiological study (EPS) results of those with preexcitation.
Methods
Patients with confirmed Danon disease diagnosed with preexcitation (PR ≤120 ms, delta wave, QRS >110 ms) on ECG were included from a multicenter registry. The incidence of arrhythmias, implantable cardioverter-defibrillator (ICD) procedures, ICD shocks, and EPS results were collected.
Results
Thirteen of 40 patients (32.5%) with Danon disease were found to have preexcitation (mean age 17.3 years; 38% women). EPS performed in 9 of 13 patients (69%) demonstrated FVP only in 2 (22.2%), extranodal pathway without exclusion of FVP in 2 (22.2%), and both FVP and extranodal pathway in 5 (55.6%). Two patients had malignant accessory pathway (AP) properties. Over median follow-up of 842 days (interquartile range 138-1678), 11 patients (85%) had ICD placement, and 6 (46.1%) underwent heart transplantation. No patients required therapy for ventricular tachycardia, and 2 patients (15%) had paroxysmal atrial fibrillation.
Conclusion
In a large multicenter cohort of patients with Danon disease, there was a high prevalence of FVP and extranodal pathways diagnosed on EPS in those with preexcitation. These findings suggest patients with preexcitation and Danon disease should undergo EPS to assess for FVP and potentially malignant extranodal AP.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1194-1202
Darden D, Hsu JC, Tzou WS, von Alvensleben JC, ... Feld GK, Adler E
Heart Rhythm: 29 Jun 2021; 18:1194-1202 | PMID: 33737230
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Impact:
Abstract

Significance of manifest localized staining during ethanol infusion into the vein of Marshall.

Takagi T, Pambrun T, Nakashima T, Vlachos K, ... Jaïs P, Derval N
Background
Localized staining due to venule injury is attributable to ethanol infusion into the vein of Marshall (Et-VOM).
Objective
The purpose of this study was to investigate adverse outcomes of localized staining during Et-VOM in patients undergoing ablation for atrial fibrillation.
Methods
Two hundred four patients (age 64 ± 10 years; 153 male) were sorted based on the aspect of localized staining. Staining of atrial myocardium that spread uniformly along the VOM vascular tree following selective VOM venography was considered normal, in contrast to predominantly localized staining that spread concentrically from a focal point due to vascular injury. Outcomes between the 2 groups were compared.
Results
Localized staining was observed in 27% of patients. No patients developed clinically significant pericardial effusions during Et-VOM; however, 7 patients developed pericardial effusions on the first postprocedural day (3.6% in patients with vs 3.4% in patients without localized staining). No significant difference was found in achievement of acute mitral isthmus (MI) block (96% vs 98%) and size of the endocardial low-voltage area (8.5 ± 4.1 cm2 vs 9.3 ± 5.3 cm2) in patients with and without localized staining, respectively. Long-term follow-up was not impacted by localized staining. Freedom from recurrent atrial tachyarrhythmias (66% vs 76%) and durability of MI block (57% vs 54%) were not significantly different with and without localized staining. There were no cases of rehospitalization for pericarditis, chronic pericardial effusion, or heart failure.
Conclusion
In our study, localized staining was frequent but was not associated with clinically relevant impact or disadvantages.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1057-1063
Takagi T, Pambrun T, Nakashima T, Vlachos K, ... Jaïs P, Derval N
Heart Rhythm: 29 Jun 2021; 18:1057-1063 | PMID: 33741483
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Impact:
Abstract

Differentiating atrial tachycardias with centrifugal activation: Lessons from high-resolution mapping.

Takigawa M, Takagi T, Martin CA, Derval N, ... Sasano T, Jais P
Background
Centrifugal activation is not always the origin of a focal atrial tachycardia (AT) (\"true-focal\"), but passive activation from the other structures (\"pseudo-focal\").
Objective
We aimed to establish a method to differentiate true-focal from pseudo-focal.
Methods
In 49 centrifugal activations in 35 patients with AT, 12-lead electrocardiogram, activation map, atrial global activation histogram (GAH), and local electrograms were analyzed. GAH demonstrates the relation between the activation area and timing through the cycle length, displayed with a normalized value, ranging from 0 (smallest activation area) to 1.0 (largest activation area).
Results
Of 30 centrifugal activations observed in the septal region, 6/30 (20.0%) were true-focal. The remaining 24/60 (80.0%) were pseudo-focal, of which 23 (95.8%) were from the opposite chamber. P-wave/flutter-wave duration < 200 ms discriminated true-focal from pseudo-focal (sensitivity 100%; specificity 54.5%; positive predictive value 33.3%; negative predictive value 100%). Multiple breakthrough ruled out the possibility of a true-focal AT. Other differentiating factors were an activation area within the initial 20 ms of <5 mm2 and a typical QS pattern electrogram at the origin. Of 19 centrifugal activations observed outside the septal regions, 7 were true-focal and 12 were pseudo-focal exited from an epicardial structure: 10 of 12 (83.3%) were located around the left atrial appendage and ridge. Flutter wave, GAH score ≤ 0.05, and GAH score < 0.1 for >110 ms of cycle length differentiated true-focal from pseudo-focal with a sensitivity/negative predictive value of 100%. GAH score < 0.1 for >40% of the cycle length simply discriminated true-focal from pseudo-focal with 100% accuracy.
Conclusion
Centrifugal activation is not necessarily due to a focal AT but passive activation. The activation map with GAH in addition to the 12-lead electrocardiogram and local electrograms enables an accurate differentiation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1122-1131
Takigawa M, Takagi T, Martin CA, Derval N, ... Sasano T, Jais P
Heart Rhythm: 29 Jun 2021; 18:1122-1131 | PMID: 33794392
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Impact:
Abstract

Association of SGLT2 inhibitors with arrhythmias and sudden cardiac death in patients with type 2 diabetes or heart failure: A meta-analysis of 34 randomized controlled trials.

Fernandes GC, Fernandes A, Cardoso R, Penalver J, ... Myerburg RJ, Goldberger JJ
Background
Sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce hospitalizations and death from heart failure (HF), but their effect on arrhythmia expression has been poorly investigated.
Objective
The purpose of this study was to evaluate the association of SGLT2is with arrhythmias in patients with type 2 diabetes mellitus (T2DM) or HF.
Methods
We searched PubMed and ClinicalTrials.gov. Two independent investigators identified randomized double-blind trials that compared SGLT2is with placebo or active control for adults with T2DM or HF. Primary outcomes were incident atrial arrhythmias, ventricular arrhythmias (VAs), and sudden cardiac death (SCD).
Results
We included 34 randomized (25 placebo-controlled and 9 active-controlled) trials with 63,166 patients (35,883 SGLT2is vs 27,273 control: mean age 53-67 years; 63% male). Medications included canagliflozin, dapagliflozin, empagliflozin, or ertugliflozin. Except for 1 study of HF, all patients had T2DM. Follow-up ranged from 24 weeks to 5.7 years. The cumulative incidence of events was low: 3.6, 1.4, and 2.5 per 1000 patient-years for atrial arrhythmias, VAs and SCD, respectively. SGLT2i therapy was associated with a significant reduction in the risk of incident atrial arrhythmias (odds ratio 0.81; 95% confidence interval 0.69-0.95; P = .008) and the \"SCD\" component of the SCD outcome (odds ratio 0.72; 95% confidence interval 0.54-0.97; P = .03) compared with control. There was no significant difference in incident VA or the \"cardiac arrest\" SCD component between groups.
Conclusion
SGLT2is are associated with significantly reduced risks of incident atrial arrhythmias and SCD in patients with T2DM. Prospective trials are warranted to confirm the antiarrhythmic effect of SGLT2is and whether this is a class or drug-specific effect.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1098-1105
Fernandes GC, Fernandes A, Cardoso R, Penalver J, ... Myerburg RJ, Goldberger JJ
Heart Rhythm: 29 Jun 2021; 18:1098-1105 | PMID: 33757845
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Impact:
Abstract

Low-temperature electrocautery reduces adverse effects from secondary cardiac implantable electronic device procedures: Insights from the WRAP-IT trial.

Mittal S, Wilkoff BL, Poole JE, Kennergren C, ... Holbrook R, Tarakji KG
Background
Cardiac device procedures require tissue dissection to free existing device lead(s). Common techniques include blunt dissection, standard electrocautery, and low-temperature electrocautery (PlasmaBlade, Medtronic); however, data on the type of electrosurgical tool used and the development of procedure- or lead-related adverse events are limited.
Objective
The purpose of this study was to determine whether standard or low-temperature electrocautery impacts the development of an adverse event.
Methods
We evaluated patients enrolled in WRAP-IT (Worldwide Randomized Antibiotic EnveloPe Infection PrevenTion Trial) undergoing cardiac implantable electronic device (CIED) revision, upgrade, or replacement. All adverse events were adjudicated by an independent physician committee. Data were analyzed using Cox proportional hazard regression modeling.
Results
In total, 5641 patients underwent device revision/upgrade/replacement. Electrocautery was used in 5205 patients (92.3%) (mean age 70.6 ± 12.7 years; 28.8% female), and low-temperature electrocautery was used in 1866 patients (35.9%). Compared to standard electrocautery, low-temperature electrocautery was associated with a 23% reduction in the incidence of a procedure- or lead-related adverse event through 3 years of follow up (hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.65-0.91; P = .002). After controlling for the number of active leads, degree of capsulectomy, degree of lead dissection, and renal dysfunction, low-temperature electrocautery was associated with a 32% lower risk of lead-related adverse events (HR 0.68; 95% CI 0.52-0.89; P = .004). These effects were consistent across a spectrum of lead-related adverse event types.
Conclusion
This study represents one of the largest assessments of electrocautery use in patients undergoing CIED revision, upgrade, or replacement procedures. Compared to standard electrocautery, low-temperature electrocautery significantly reduces adverse effects from these procedures.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1142-1150
Mittal S, Wilkoff BL, Poole JE, Kennergren C, ... Holbrook R, Tarakji KG
Heart Rhythm: 29 Jun 2021; 18:1142-1150 | PMID: 33781980
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Impact:
Abstract

Vein of Marshall ethanol infusion in the treatment of atrial fibrillation: From concept to clinical practice.

Valderrábano M
The vein of Marshall (VOM) contains innervation, myocardial connections, and arrhythmogenic foci that make it an attractive target in catheter ablation of atrial fibrillation (AF). Additionally, it co-localizes with the mitral isthmus, which is critical to sustain perimitral flutter, and is a true atrial vein that communicates with underlying myocardium. Retrograde balloon cannulation of the VOM from the coronary sinus is feasible and allows for ethanol delivery, which results in rapid ablation of neighboring myocardium and its innervation. Here we review the body of work performed over a span of 13 years, from the inception of the technique, to its preclinical validation, to demonstration of its ablative and denervation effects, and finally to completion of a randomized clinical trial demonstrating favorable outcomes, improving rhythm control in catheter ablation of persistent AF.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1074-1082
Valderrábano M
Heart Rhythm: 29 Jun 2021; 18:1074-1082 | PMID: 33781979
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Impact:
Abstract

Defining idiopathic ventricular fibrillation: A systematic review of diagnostic testing yield in apparently unexplained cardiac arrest.

Alqarawi W, Dewidar O, Tadros R, Roberts JD, ... Wells G, Krahn AD
Background
Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with apparently unexplained cardiac arrest (UCA) after varying degrees of evaluation. This is largely due to the lack of a standardized approach to UCA.
Objective
We sought to develop an evidence-based diagnostic algorithm for IVF by systematically examining the yield of diagnostic testing in UCA probands.
Methods
Studies reporting the yield of diagnostic testing in UCA were identified in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and conference abstracts. Their methodological quality was assessed by the National Institutes of Health quality assessment tool. Meta-analyses were performed using the random effects model.
Results
A total of 21 studies were included. The pooled comprehensive diagnostic testing yield was 43% (95% confidence interval 39%-48%). A lower yield was seen when only definite diagnoses based on the prespecified criteria were used (32% vs 47%; P = .15). Epinephrine challenge, Holter monitoring, and family screening were associated with low yield (<5%), whereas cardiac magnetic resonance imaging, exercise treadmill test, and sodium-channel blocker challenge were associated with high yield (≥5%). Coronary spasm provocation, electrophysiology study, and systematic genetic testing were reported to be abnormal in a high proportion of UCA probands (>10%).
Conclusion
We developed a stepwise algorithm for UCA evaluation and criteria to assess the strength of IVF diagnosis on the basis of the diagnostic yield of UCA testing.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1178-1185
Alqarawi W, Dewidar O, Tadros R, Roberts JD, ... Wells G, Krahn AD
Heart Rhythm: 29 Jun 2021; 18:1178-1185 | PMID: 33781978
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Impact:
Abstract

Persistent atrial fibrillation ablation in cardiac laminopathy: Electrophysiological findings and clinical outcomes.

Chauvel R, Derval N, Duchateau J, Denis A, ... Haïssaguerre M, Pambrun T
Background
Little is known about persistent atrial fibrillation (AF) ablation in patients with cardiac laminopathy (CLMNA).
Objectives
We aimed to characterize atrial electrophysiological properties and to assess the long-term outcomes of persistent AF ablation in patients with CLMNA.
Methods
All patients with CLMNA referred in our center for persistent AF ablation were retrospectively included. Left atrial (LA) volume, left atrial appendage (LAA) cycle length, interatrial conduction delay, and LA voltage amplitude were analyzed during the ablation procedure. Sinus rhythm maintenance and LA contractile function were assessed during long-term follow-up.
Results
From 2011 to 2020, 8 patients were included. The mean age was 47 ± 14 years, and 3 patients (38%) were women. The LA volume was 205.8 ± 43.7 mL; the LAA AF cycle length was 250.7 ± 85.6 ms; and the interatrial conduction delay was 296.5 ± 110.1 ms. Large low-voltage areas (>50% of the LA surface; <0.5 mV electrogram) were recorded in all 8 patients. Two patients had inadvertent LAA disconnection during ablation. All A waves recorded by pulsed Doppler in sinus rhythm were <30 cm/s before and after AF ablation. Early arrhythmia recurrence was recorded in 7 patients (87%) (time to recurrence 4 ± 4 months; 1.5 procedures per patient). After a mean follow-up of 4.4 ± 3.2 years, 4 patients underwent implantable cardioverter-defibrillator therapy for life-threatening ventricular arrhythmia and 3 patients finally underwent heart transplantation.
Conclusion
Patients with persistent AF afflicted by CLMNA exhibit severe LA impairment because of large low-voltage areas, prolonged conduction velocity, and reduced contractile function. Ablation procedures have a limited effect with a high recurrence rate.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1115-1121
Chauvel R, Derval N, Duchateau J, Denis A, ... Haïssaguerre M, Pambrun T
Heart Rhythm: 29 Jun 2021; 18:1115-1121 | PMID: 33812085
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Impact:
Abstract

Left atrial appendage closure in patients with prohibitive anatomy: Insights from PINNACLE FLX.

Ellis CR, Jackson GG, Kanagasundram AN, Mansour M, ... Doshi S, Osorio J
Background
Watchman 2.5 (Boston Scientific Inc, Marlborough, MA) implant success approaches 95% in registries, yet many patients are not attempted because of complex left atrial appendage (LAA) anatomy. Watchman FLX can expand the range of ostium width (14-31.5 mm) and depth available for LAA closure.
Objective
The purpose of this study was to evaluate the safety and efficacy of Watchman FLX in patients with a failed Watchman 2.5 attempt or prohibitive LAA anatomy.
Methods
The roll-in (n = 58) and primary effectiveness (n = 400) cohorts of the PINNACLE FLX trial comprised the study population. Subjects were identified who previously failed implantation of Watchman 2.5 (n = 11) or were not attempted because of prohibitive LAA anatomy (n = 88). Demographic characteristics, implant procedure details, and TEE follow-up data were compared to controls composed of enrollees not meeting these criteria (n = 359).
Results
Watchman FLX LAA closure was successfully implanted in all subjects with a prior failed Watchman 2.5 attempt (n = 11 of 11). Subjects with previously failed Watchman 2.5 were more likely to receive a 35 mm FLX device than controls (27.3% vs 7.3%; P = .047). Patients with prohibitive anatomy had smaller LAA dimensions than did controls (diameter 18.0 ± 4 mm vs 20.4 ± 3 mm; P < .001 and length 23.7 ± 5 mm vs 28.9 ± 5 mm; P < .001). There was no difference in age, sex, CHA2DS2-VASc score, HAS-BLED score, or primary efficacy between cohorts. Transesophageal echocardiography (TEE) at 12 months showed zero leak in 90.9% in the failed Watchman 2.5 cohort, 91.3% in the prohibitive anatomy cohort, and 89.5% in the control cohort (P = .84). Overall and cardiovascular mortality was lower in the prohibitive anatomy cohort (1.2% vs 8.8% in controls; P = .02).
Conclusion
Watchman FLX implantation in patients with a prior failed Watchman 2.5 attempt or prohibitive LAA anatomy remained safe and highly effective. The association of reduced overall mortality with smaller LAA dimension warrants future study.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1153-1161
Ellis CR, Jackson GG, Kanagasundram AN, Mansour M, ... Doshi S, Osorio J
Heart Rhythm: 29 Jun 2021; 18:1153-1161 | PMID: 33957090
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Impact:
Abstract

The combination of coronary sinus ostial atresia/abnormalities and a small persistent left superior vena cava-Opportunity for left ventricular lead implantation and unrecognized source of thromboembolic stroke.

Zou F, Worley SJ, Steen T, McKillop M, ... Hadadi CA, Kushnir A
Background
Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ventricular (LV) lead implantation. Some patients with CS ostial abnormalities also have a small persistent left superior vena cava (sPLSVC).
Objective
The purpose of this study was to describe CS ostial abnormalities and sPLSVC as an opportunity for LV lead implantation and unrecognized source of stroke.
Methods
Twenty patients with CS ostial abnormalities and sPLSVC were identified. Clinical information, imaging methods, LV lead implantation techniques, and complications were summarized.
Results
Forty percent had at least 1 previously unsuccessful LV lead placement. In 70%, sPLSVC was identified by catheter manipulation and contrast injection in the left brachiocephalic vein, and in 30% by levophase CS venography. In 30%, sPLSVC was associated with drainage from the CS into the left atrium (LA). When associated with CS ostial abnormalities, the sPLSVC diameter averaged 5.6 ± 3 mm. sPLSVC was used for successful LV lead implantation in 90% of cases. In 80%, the LV lead was implanted down sPLSVC, and in 20%, sPLSVC was used to access the CS from the RA. Presumably because of unrecognized drainage from the CS to the LA, 1 patient had a stroke during implantation via sPLSVC.
Conclusion
When CS ostial abnormalities prevent access to the CS from the RA, sPLSVC can be used to successfully implant LV leads. In some, the CS partially drains into the LA and stroke can occur spontaneously or during lead intervention. It is important to distinguish sPLSVC associated with CS ostial abnormalities from isolated PLSVC.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Jun 2021; 18:1064-1073
Zou F, Worley SJ, Steen T, McKillop M, ... Hadadi CA, Kushnir A
Heart Rhythm: 29 Jun 2021; 18:1064-1073 | PMID: 33971333
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Impact:
Abstract

Catheter ablation of premature ventricular complexes associated with left ventricular false tendons.

Zhang J, Liang M, Wang Z, Zhang X, ... Zhang H, Huang J
Background
Clinical studies have suggested that there is a significant correlation between left ventricular(LV) false tendon and premature ventricular complexes(PVCs).
Objective
This study aimed to investigate the electrophysiological characteristics and the outcome of RFCA for this category of PVCs.
Methods
From a total of 2284 patients with idiopathic PVCs who underwent catheter ablation at six institutions in China, ICE was utilized during the procedure in 346 cases, ten patients (2.9%) with PVCs associated with false tendon were retrospectively reviewed and enrolled in the present study. Activation mapping and pace mapping were performed to localize the origin of PVCs. Intracardiac echocardiography (ICE) was used in all patients.If the false tendon was directly visualized and identified, we attempted to identify the distinct relationship with the PVC origin.
Results
The PVCs were successfully eliminated by ablation in all patients.The target sites were confirmed to be related to false tendon . The origin of PVCs was located at the attachment of the false tendon to the papillary muscle, LV septum or LV apex. At the target site, high-frequency Purkinje potentials were observed preceding local ventricular activation in seven patients.
Conclusions
LV false tendon can be associated with PVCs which can be cured by RFCA.. An ICE-guided electroanatomical approach should be considered to improve the safety and feasibility of this procedure.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 28 Jun 2021; epub ahead of print
Zhang J, Liang M, Wang Z, Zhang X, ... Zhang H, Huang J
Heart Rhythm: 28 Jun 2021; epub ahead of print | PMID: 34214648
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Impact:
Abstract

Subcutaneous implantable cardioverter defibrillator and defibrillation testing: a propensity-matched pilot study.

Forleo GB, Gasperetti A, Breitenstein A, Laredo M, ... Badenco N, Biffi M
Background
To date, only few comparisons between subcutaneous implantable cardioverter defibrillator (S-ICD) patients undergoing vs. not undergoing defibrillation testing (DT) at implantation (DT+ vs DT-) have been reported.
Objective
Aim of the study was to compare long-term clinical outcomes of two propensity-matched cohorts of DT+ and DT- patients.
Methods
Among consecutive S-ICD patients, implanted across 17 centers from January 2015 to October 2020, DT- patients were 1:1 propensity-matched for baseline characteristics with DT+ patients. The primary outcome was a composite of ineffective shocks and cardiovascular mortality. Appropriate and inappropriate shock rates were deemed secondary outcomes.
Results
Among 1290 patients, a total of 566 propensity-matched patients (n=283 DT+; n=283 DT-) served as study population. Over a median follow-up of 25.3 months, no significant differences in primary outcome event rates were found (n=10 DT+ vs n=14 DT-; p=0.404) as well as for ineffective shocks (n=5 DT- vs n=3 DT+; p=0.725). At multivariable Cox regression analysis, DT performance was neither associated with a reduction of the primary combined outcome, nor of ineffective shocks at follow-up. A high PRAETORIAN score was positively associated with both the primary outcome (HR=3.976 [1.339-11.802] p=0.013) and ineffective shocks alone at follow-up (HR=19.030 [4.752-76.203] p=0.003).
Conclusion
In two cohorts of strictly propensity-matched patients, DT performance was not associated with significant differences in cardiovascular mortality and ineffective shocks. The PRAETORIAN score resulted capable of correctly identifying a large percentage of the patients at risk of ineffective shock conversion in both cohorts.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 28 Jun 2021; epub ahead of print
Forleo GB, Gasperetti A, Breitenstein A, Laredo M, ... Badenco N, Biffi M
Heart Rhythm: 28 Jun 2021; epub ahead of print | PMID: 34214647
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Impact:
Abstract

Role of endocardial ablation in eliminating an epicardial arrhythmogenic substrate in patients with Brugada syndrome.

Kamakura T, Cochet H, Juhoor M, Nakatani Y, ... Haïssaguerre M, Hocini M
Background
Epicardial ablation is occasionally limited by coronary artery (CA) injuries or epicardial fat (EF).
Objective
The purpose of this study was to evaluate the anatomic obstacles that prevent ablation of epicardial abnormal potentials (EAPs) in patients with Brugada syndrome (BrS) and to investigate the feasibility of EAP elimination by endocardial right ventricular (RV) ablation.
Methods
This study included 16 BrS patients with previous ventricular fibrillation (VF), including 10 with an electrical storm. Data from multidetector computed tomography were assessed, and the proximity of the CA and EF was correlated with EAPs.
Results
EAPs were present in the epicardial RV outflow tract and RV inferior wall in all patients and 12 patients (75%), respectively. These EAPs were present within 5 mm of the main body and branches of the right CA in 14 patients (87.5%). However, only 1.4% ± 2.9% of the EAP area was covered with thick EF (≥8 mm). Partial EAP elimination by endocardial RV ablation was feasible in all 10 patients, with 53.3% successful endocardial RV radiofrequency applications for eliminating EAPs. After the procedure, VF remained inducible in 37.5% of the patients. During the 25.1 ± 29.1 months of follow-up, no patients experienced an electrical storm, and VF burden significantly decreased (median VF episodes before and after ablation: 7 and 0, respectively).
Conclusion
EAPs are near the CA in most BrS patients, thereby requiring caution during epicardial ablation, whereas EF is less of an issue. Endocardial ablation is feasible to eliminate some EAPs and may be combined with epicardial ablation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 25 Jun 2021; epub ahead of print
Kamakura T, Cochet H, Juhoor M, Nakatani Y, ... Haïssaguerre M, Hocini M
Heart Rhythm: 25 Jun 2021; epub ahead of print | PMID: 34182174
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Impact:
Abstract

Atrial Heat Shock Protein levels are associated with early post-operative and persistence of atrial fibrillation.

Marion DMSV, Ramos KS, Lanters EAH, Bulte LB, ... de Groot NMS, Brundel BJJM
Background
Early detection and staging of atrial fibrillation (AF) is of importance for clinical management. Serum (bio)markers, such as heat shock proteins (HSP), may enable AF staging and identify patients at risk for AF recurrence and post-operative AF (PoAF).
Objective
This study evaluates the relation between serum and atrial tissue HSP levels, stages of AF, AF recurrence after treatment and PoAF from patients undergoing cardiothoracic surgery.
Methods
Patients without (control) and with paroxysmal (ParAF), persistent (PerAF) or longstanding persistent (LSPerAF) AF were included. HSPB1, HSPA1, HSPB7 and HSPD1 levels were measured in serum obtained prior to and post intervention. HSPB1, HSPA1, HSPA5, HSPD1, HSPB5 and pHSF1 levels were measured in left and/or rightatrial appendages (respectively LAA and RAA).
Results
In RAA, HSPA5 levels were significantly lower in LSPerAF and HSPD1 levels significantly higher in PerAF patients compared to controls. In RAA of controls who developed PoAF, HSPA1 and HSPA5 levels were significantly higher compared to those without PoAF. Also, HSPB1 RAA levels were lower and HSPA5 LAA levels higher in patients undergoing arrhythmia surgery who developed AF recurrence within 1 week after surgery compared to patients who did not.
Conclusions
HSPA5 RAA and HSPD1 RAA and LAA levels are altered in persistent stages of AF. RAA HSPA1 and HSPA5 levels associate with development of PoAF. Additionally, HSPB1 RAA and HSPA5 LAA levels can predict AF recurrence in patients who underwent arrhythmia surgery. Nevertheless, HSP levels in serum cannot discriminate AF stages from controls, predict PoAF nor AF recurrence after treatment.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 25 Jun 2021; epub ahead of print
Marion DMSV, Ramos KS, Lanters EAH, Bulte LB, ... de Groot NMS, Brundel BJJM
Heart Rhythm: 25 Jun 2021; epub ahead of print | PMID: 34186247
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Impact:
Abstract

Mechanisms and outcomes of catheter ablation for biatrial tachycardia in adults with congenital heart disease.

Moore JP, Bowman H, Gallotti RG, Shannon KM
Background
Biatrial tachycardia (BiAT) is a rare form of macroreentry not previously characterized in adults with congenital heart disease (ACHD).
Objective
The purpose of this study was to determine the prevalence, mechanisms, and outcomes of catheter ablation for BiAT in ACHD.
Methods
All ACHD undergoing catheter ablation for macroreentrant atrial tachycardia over a 10-year period were evaluated for evidence of BiAT. Patients were categorized as prior Senning, Fontan, or other biventricular operation. A novel biatrial global activation histogram (GAH) analysis was used to demonstrate the presence of interatrial connections (IACs).
Results
Among 263 ACHD, BiAT was identified at 11 procedures in 10 patients (4.2%; median age 35 years; 30% male). The congenital category was Fontan in 6, Senning in 3, and biventricular in 2. Diagnosis of BiAT was associated with ablation era and mapping technology (P <.001) and could be confirmed with a novel GAH mapping approach for normally septated atrial connections. Catheter ablation targeted an IAC in 5 cases (Bjork Fontan/biventricular operations), a posterior isthmus in 3 (Senning operation), and the cavotricuspid isthmus or equivalent in 3 (lateral tunnel [LT] Fontan). Recurrence was isolated to ablation to sites at the expected location of the Bachmann bundle, and durable success could be achieved after repeat ablation.
Conclusion
BiAT occurs in approximately 4% of ACHD but likely is significantly underrecognized. BiAT could be targeted at an IAC after biventricular heart/Bjork modified Fontan operations and at a conventional critical isthmus after Senning and LT Fontan operations.

Published by Elsevier Inc.

Heart Rhythm: 24 Jun 2021; epub ahead of print
Moore JP, Bowman H, Gallotti RG, Shannon KM
Heart Rhythm: 24 Jun 2021; epub ahead of print | PMID: 34182173
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Impact:
Abstract

Atrial pacing in Fontan patients: The effect of transvenous lead on clot burden.

Assaad IE, Pastor T, O\'Leary E, Gauvreau K, ... DeWitt ES, Mah DY
Background
Transvenous permanent pacemaker (PPM) implantation is an available option for Fontan patients with sinus node dysfunction. However, the thrombogenic potential of leads within the Fontan baffle is unknown.
Objective
The purpose of this study was to compare the clot burden in Fontan patients with a transvenous atrial PPM to those without a PPM and those with an epicardial PPM.
Methods
This was a retrospective cohort study of all transvenous PPM implantations in Fontan patients followed at our institution (2000-2018). We performed frequency matching on Fontan type and age group. Primary outcome was identification of intracardiac clot, pulmonary embolus, or embolic stroke.
Results
Of 1920 Fontan patients, 58 patients (median age 23 years; interquartile range [25th-75th percentiles] 14-33) at the time of transvenous PPM implantation and 174 matched subjects formed our cohort. The type of Fontan performed in case subjects was right atrium-pulmonary artery or right atrium-right ventricle conduit (54%), lateral tunnel (43%), and extracardiac (3%). The cumulative incidence of clot was highest in patients with transvenous PPM, followed by patients with epicardial PPM and no PPM (1.2 vs 0.87 vs 0.67 per 100 person-years of follow-up, respectively). In multivariable analysis, anticoagulation and/or antiplatelet therapy were protective against clot and resulted in reduction of clot risk by 3-fold (incidence rate ratio 0.33; 95% confidence interval 0.21-0.53; P <.001).
Conclusion
In a large cohort of Fontan patients matched for age and Fontan type, patients with transvenous PPM had a higher but not statistically significant incidence of clot compared to those with no PPM and epicardial PPM. Patients treated with warfarin/aspirin had lower clot risk.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 24 Jun 2021; epub ahead of print
Assaad IE, Pastor T, O'Leary E, Gauvreau K, ... DeWitt ES, Mah DY
Heart Rhythm: 24 Jun 2021; epub ahead of print | PMID: 34182172
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Impact:
Abstract

Deficiency of CXXC finger protein 1 leads to small changes in heart rates but moderate epigenetic alterations and significant protein downregulation of hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) ion channels in mice.

Shi L, Shen J, Jin X, Li Z, ... Yang B, Pan Z
Background
The normal cardiac rhythm is generated in the sinoatrial node (SAN). Changes in ionic currents of the SAN may cause sinus arrhythmia. CXXC finger protein 1 (Cfp1) is an epigenetic regulator that involves in the transcriptional regulation of multiple genes.
Objectives
The study aims to explore whether Cfp1 controls SAN function through regulation of ion channel-related genes.
Methods
The electrophysiological study, patch clamp recording, RT-PCR, optical mapping, chromatin immunoprecipitation and immunofluorescence staining were performed to evaluate the function of SAN and underlying mechanism on Cfp1 heterozygous knockout (Cfp1+/-) mice.
Results
The heart rate was slower slightly, and the SAN recovery time was longer in Cfp1+/- mice than controls. Whole-cell patch-clamp recording showed that the firing rate of action potential was reduced in Cfp1+/- mice. The density of If current was reduced by 66% in SAN cells of Cfp1+/- mice but the densities of ICa, ICa-L and ICa-T were not changed. The HCN4 mRNA level in SAN tissue of Cfp1+/- mice was reduced. The HCN4 protein was significantly decreased in SAN cells and tissues after heterozygous deletion of Cfp1. The chromatin immunoprecipitation assay on cultured HL-1 cells demonstrated that Cfp1 was enriched in the promoter regions of HCN4. Knockdown of Cfp1 reduced H3K4 trimethylation, H3K9 acetylation and H3K27 acetylation of HCN4 promoter region.
Conclusion
Deficiency of Cfp1 leads to small changes in heart rates but moderate epigenetic modification alterations and significant protein downregulation of HCN4 ion channels in mice.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 24 Jun 2021; epub ahead of print
Shi L, Shen J, Jin X, Li Z, ... Yang B, Pan Z
Heart Rhythm: 24 Jun 2021; epub ahead of print | PMID: 34182171
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Impact:
Abstract

On the Safety, Efficacy and Monitoring of Bipolar Radiofrequency ablation in Beating Myopathic Human and Healthy Swine Hearts.

Bhaskaran A, Niri A, Azam MA, Nayyar S, ... Ha A, Nanthakumar K
Background
Safety and efficacy parameters for bipolar RF ablation is not well defined.
Objective
To study the safe range of power, the utility of trans-myocardial bipolar EGM amplitude and circuit impedance in ablation monitoring.
Methods
Sixteen beating ex vivo Human and Swine hearts were studied in the Langendorff set up. Ninety-two bipolar ablations using two, 4mm irrigated catheters were performed with the settings of 20-50W, 60s, 30ml/min irrigation in the left ventricle.
Results
For low-power ablations (20 & 30W), transmurality was observed in 29/38 (76%) and 10/28 (36%) ablations for tissue thickness ≤17mm and >17mm, respectively. For high-power ablations (40 & 50W), transmurality was observed in 5/7 (71%) and 7/19 (37%) ablations for tissue thickness ≤17mm and >17mm, respectively. Steam pop occurrence for low and high-power ablations were 11/66 (16%) and 16/26 (62%), (p=0.0001) respectively. Lesion depth (limited by transmurality) was 12.0 ± 5.7 and 12.3 ± 5.8mm, (p=1). Trans-myocardial EGM amplitude decrement >60% strongly predicted transmurality (AUC 0.8) and circuit impedance decrement >26% predicted steam pops (AUC 0.75). Half normal saline did not affect transmurality or incidence of steam pops compared to normal saline irrigation.
Conclusion
Bipolar RF ablation of 20-30W power provided an ideal balance of safety and efficacy, whereas power ≥40W should be used with caution due to the high incidence of steam pops. Lesion transmurality monitoring and steam pop avoidance were best achieved using trans-myocardial bipolar EGM voltage and circuit impedance respectively.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 24 Jun 2021; epub ahead of print
Bhaskaran A, Niri A, Azam MA, Nayyar S, ... Ha A, Nanthakumar K
Heart Rhythm: 24 Jun 2021; epub ahead of print | PMID: 34182170
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Impact:
Abstract

The Aorticorenal Ganglion as a Novel Target for Renal Neuromodulation.

Hori Y, Temma T, Wooten C, Sobowale C, ... Peacock W, Ajijola OA
Background
Clinical trials for renal artery (RA) ablation have shown limited efficacy.
Objective
We investigated whether the aorticorenal ganglion (ARG) can be targeted for renal denervation.
Methods
Twenty-eight pigs were studied under isoflurane or alpha-chloralose to examine hemodynamic responses and catecholamine release in response to RA or ARG stimulation. To assess the efficacy of ARG ablation, we randomized 16 pigs to either sham, RA, or ARG ablation, followed by occlusion of the left anterior descending coronary artery (LAD). Hemodynamic responses, cardiac electrophysiologic parameters, and arrhythmias/sudden cardiac death were assessed following LAD occlusion. Absent hemodynamic responses to stimulation confirmed ARG or RA ablation. In vivo stellate ganglion neural activity was recorded to assess cardiac sympathetic signaling. Cadaveric dissections were performed to localize the ARG in humans for comparison to swine.
Results
The ARG is a purely sympathetic ganglion with cholinergic inputs and pass-through sensory afferent fibers. Compared to RA stimulation, ARG stimulation yielded greater hemodynamic responses during alpha-chloralose anesthesia. However, neither site yielded significant responses under isoflurane. Radiofrequency ablation of the ARG eliminated responses to both RA and ARG stimulation, whereas RA ablation did not eliminate responses to ARG stimulation. Ablation of the ARG did not impact the kidneys or adrenal glands. Compared to Control and RA ablation, ARG ablation was protective against ventricular arrhythmias and sudden death. Human and swine ARG are similar located in the aorticorenal region.
Conclusions
Our findings indicate that the ARG may be a novel target for renal neuromodulation. Further studies are warranted to validate these findings.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 24 Jun 2021; epub ahead of print
Hori Y, Temma T, Wooten C, Sobowale C, ... Peacock W, Ajijola OA
Heart Rhythm: 24 Jun 2021; epub ahead of print | PMID: 34182169
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Impact:
Abstract

Simple electrophysiological predictor of QRS change induced by cardiac resynchronization therapy: A novel marker of complete left bundle branch block.

Sedláček K, Jansová H, Vančura V, Grieco D, Kautzner J, Wichterle D
Background
QRS complex shortening by cardiac resynchronization therapy (CRT) has been associated with improved outcomes.
Objective
We hypothesized that the absence of QRS duration (QRSd) prolongation by right ventricular mid-septal pacing (RVP) may indicate complete left bundle branch block (cLBBB).
Methods
We prospectively collected 12-lead surface electrocardiograms (ECGs) and intracardiac electrograms during CRT implant procedures. Digital recordings were edited and manually measured. The outcome measure was a change in QRSd induced by CRT (delta CRT). Several outcome predictors were investigated: native QRSd, cLBBB (by using Strauss criteria), interval between the onset of the QRS complex and the local left ventricular electrogram (Q-LV), and a newly proposed index defined by the difference between RVP and native QRSd (delta RVP).
Results
One hundred thirty-three consecutive patients were included in the study. Delta RVP was 27 ± 25 ms, and delta CRT was -14 ± 28 ms. Delta CRT correlated with native QRSd (r = -0.65), with the presence of ECG-based cLBBB (r = -0.40), with Q-LV (r = -0.68), and with delta RVP (r = 0.72) (P < .00001 for all correlations). In multivariable analysis, delta CRT was most strongly associated with delta RVP (P < .00001), followed by native QRSd and Q-LV, while ECG-based cLBBB became a nonsignificant factor.
Conclusion
Baseline QRSd, delta RVP, and LV electrical lead position (Q-LV) represent strong independent predictors of ECG response to CRT. The absence of QRSd prolongation by RVP may serve as an alternative and more specific marker of cLBBB. Delta RVP correlates strongly with the CRT effect on QRSd and outperforms the predictive value of ECG-based cLBBB.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 21 Jun 2021; epub ahead of print
Sedláček K, Jansová H, Vančura V, Grieco D, Kautzner J, Wichterle D
Heart Rhythm: 21 Jun 2021; epub ahead of print | PMID: 34098086
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Impact:
Abstract

Substrate characterization of the right ventricle in repaired tetralogy of Fallot using late enhancement cardiac magnetic resonance.

Rivas-Gándara N, Dos-Subirá L, Francisco-Pascual J, Rodríguez-García J, ... Rodríguez-Palomares J, Ferreira-González I
Background
Three-dimensional (3D) substrate characterization by high-resolution late gadolinium enhancement cardiac magnetic resonance (LE-CMR) is useful for guiding ventricular tachycardia ablation of the left ventricle in ischemic heart disease.
Objective
The purpose of this study was to validate the substrate characterization and 3D reconstruction of LE-CMR images of the right ventricle (RV) in patients with repaired tetralogy of Fallot (rTOF) and to identify the algorithm that best fits with electroanatomic mapping (EAM).
Methods
RV LE-CMR images were compared with RV EAM in 10 patients with rTOF. RV LE-CMR images were postprocessed and analyzed to identify fibrotic tissue on 3D color maps. The 3D RV substrate reconstructions were created using an adjustable percentage of the maximum voxel signal intensity (MSI) of the scar region to define the threshold between core, transitional zone (TZ), and healthy tissue. Extensions of the core and TZ areas were compared with the scar (<0.5 mV) and low-voltage (0.5-1.5 mV) areas obtained by RV EAM. Agreement on anatomic isthmi identification was quantified.
Results
The best match between core and scar was obtained at 65% MSI cutoff (mean areas 17.4 ± 9.9 cm2 vs 16.9 ± 10.0 cm2, respectively; r = 0.954; P <.001). Agreement on anatomic isthmi identification was best at 60% MSI cutoff, which identified 95% of isthmi and achieved a total fit in 90% of patients.
Conclusion
This study demonstrates that characterization of the RV substrate by postprocessing LE-CMR images in rTOF patients is feasible and validates the technique against RV EAM, which could help in planning target ablation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 18 Jun 2021; epub ahead of print
Rivas-Gándara N, Dos-Subirá L, Francisco-Pascual J, Rodríguez-García J, ... Rodríguez-Palomares J, Ferreira-González I
Heart Rhythm: 18 Jun 2021; epub ahead of print | PMID: 34098087
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Impact:
Abstract

Clinical characteristics and risk of arrhythmic events in patients younger than 12 years diagnosed with Brugada syndrome.

Righi D, Porco L, Calvieri C, Tamborrino PP, ... Tozzi AE, Drago F
Background
Brugada syndrome (BrS) is an inheritable disease with an increased risk of sudden cardiac death. Although several score systems have been proposed, the management of children with BrS has been inconsistently described.
Objective
The purpose of this study was to identify the characteristics, outcome, and risk factors associated with cardiovascular and arrhythmic events (AEs) in children younger than 12 years with BrS.
Methods
In this single-center case series, all children with spontaneous or drug/fever-induced type 1 Brugada electrocardiographic (ECG) pattern and younger than 12 years at the time of diagnosis were enrolled.
Results
Forty-three patients younger than 12 years at the time of diagnosis were included. The median follow-up was 3.97 years (interquartile range 2-12 years). In terms of first-degree atrioventricular block, premature beats, nonmalignant AEs, malignant AEs, and episodes of syncope, no significant differences were observed either between patients with spontaneous and drug/fever-induced type 1 Brugada ECG pattern or between female and male patients (except a significant difference between female and male patients for first-degree atrioventricular block). A higher incidence of malignant AEs was observed in patients with syncope (3 of 8 [37.5%] vs 0 of 35 [0%]; P = .005) than in patients without syncope. SCN5A mutations were associated with a higher occurrence of malignant AEs (3 of 14 [21.4%] vs 0 of 25 [0%]; P = .04) compared with no SCN5A mutations.
Conclusion
A spontaneous type 1 Brugada ECG pattern is not associated with a higher incidence of syncope, first-degree atrioventricular block, premature beats, nonmalignant AEs, and malignant AEs than the drug/fever-induced type 1 Brugada ECG pattern. Syncope events are correlated with an increased incidence of malignant AEs. Moreover, SCN5A mutations are associated with a higher occurrence of malignant AEs.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 16 Jun 2021; epub ahead of print
Righi D, Porco L, Calvieri C, Tamborrino PP, ... Tozzi AE, Drago F
Heart Rhythm: 16 Jun 2021; epub ahead of print | PMID: 34147702
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Impact:
Abstract

Outcomes associated with pacemaker implantation following transcatheter aortic valve replacement: A nationwide cohort study.

Clementy N, Bisson A, Bodin A, Herbert J, ... Babuty D, Fauchier L
Background
Conduction abnormalities following transcatheter aortic valve replacement (TAVR) often may require permanent pacemaker implantation (PPM).
Objective
The purpose of this study was to evaluate outcomes associated with PPM after a TAVR procedure in a large, nationwide-level population.
Methods
Based on the administrative hospital discharge database, the incidence of all-cause death, cardiovascular death, and hospitalization for heart failure (HF) were retrospectively collected, based on the presence or absence of PPM, in the first 30 days following all TAVRs in France from 2010 to 2019.
Results
Among 520,662 patients hospitalized for aortic stenosis, 49,201 were treated with TAVR. A total of 29,422 patients had follow-up ≥6 months (median 1.7 years), 22% already had PPM at baseline, and 22% underwent PPM within the first 30 days post-TAVR. Adjusted hazard ratios for the combined risk of all-cause death and hospitalization for HF, during the whole follow-up, were higher in both patients with a previous PPM and in those implanted within 30 days (hazard ratio [95% confidence interval] 1.12 [1.07-1.17] and 1.11 [1.06-1.16], respectively).
Conclusion
PPM at baseline and within 30 days post-TAVR are independently associated with higher mortality and HF hospitalization during follow-up.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 16 Jun 2021; epub ahead of print
Clementy N, Bisson A, Bodin A, Herbert J, ... Babuty D, Fauchier L
Heart Rhythm: 16 Jun 2021; epub ahead of print | PMID: 34147701
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Impact:
Abstract

Smartwatch-based detection of cardiac arrhythmias: Beyond the differentiation between sinus rhythm and atrial fibrillation.

Strik M, Ploux S, Ramirez FD, Abu-Alrub S, ... Haïssaguerre M, Bordachar P
Within the span of a few years, watches have functionally morphed from objects that tell time to wearable minicomputers that allow real-time recording of electrocardiograms (ECGs). Considerable information can be deduced from these single lead tracings, and it is now not uncommon to see patients in whom diagnostic tracings of clinically relevant but elusive arrhythmias are captured using a smartwatch. Empowering individuals to record their own ECG tracings in scenarios such as palpitations, syncope, and for risk stratification of sudden death intuitively has considerable potential, but its value remains to be robustly demonstrated. The main objective of this review is to describe the information that can be obtained from smartwatch-based single-lead ECG recordings beyond simply differentiating between sinus rhythm and atrial fibrillation. We also review the strengths and limitations of using these devices in clinical settings and offer potential solutions to address the latter.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 16 Jun 2021; epub ahead of print
Strik M, Ploux S, Ramirez FD, Abu-Alrub S, ... Haïssaguerre M, Bordachar P
Heart Rhythm: 16 Jun 2021; epub ahead of print | PMID: 34147700
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Impact:
Abstract

Long-term outcomes and periprocedural safety and efficacy of percutaneous left atrial appendage closure in a United Kingdom tertiary center: An 11-year experience.

Briosa E Gala A, Pope MTB, Monteiro C, Leo M, ... Newton JD, Betts TR
Background
Left atrial appendage occlusion (LAAO) has been widely adopted as a strategy for stroke prevention in patients with atrial fibrillation ineligible for oral anticoagulation.
Objective
The purpose of this study was to explore longer-term \"real-world\" safety and efficacy outcomes in patients undergoing LAAO given varied practices in antithrombotic regimens and adoption of same-day discharge.
Methods
Analysis of acute procedural and long-term outcome data was performed for all patients undergoing LAAO implant in a United Kingdom tertiary center over an 11-year period. Rates of adverse events were calculated and compared to predicted rates in historical cohorts according to CHA2DS2-VASc and HAS-BLED scores.
Results
Device implantation was attempted in 229 patients, with an acute procedural success rate of 98.2% and low rate of major procedural complications of 2.6% at 30 days, including 1.3% procedure-related mortality. In the last year of enrollment, 75% of patients were discharged on the same day of the procedure. A strategy of early cessation of antithrombotic therapy was adopted, with a low rate of device-related thrombus. Over total follow-up of 889 patient-years, there were low rates of thromboembolic events (2.2/100 patient-years) and of significant bleeding events (intracranial bleed 0.6/100 patient-years; nonprocedural major bleeding 2.3/100 patient-years).
Conclusion
LAAO with a same-day discharge strategy and early cessation of antiplatelet therapy seems to be safe and effective in reducing the risk of stroke and major bleeding over mean follow-up approaching 4 years. Although these data are reassuring, results from randomized trials with strict shorter periods of postprocedural antithrombotic therapy are eagerly awaited.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 11 Jun 2021; epub ahead of print
Briosa E Gala A, Pope MTB, Monteiro C, Leo M, ... Newton JD, Betts TR
Heart Rhythm: 11 Jun 2021; epub ahead of print | PMID: 34126270
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Impact:
Abstract

Prevalence and outcome of early recurrence of atrial tachyarrhythmias in the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) study.

Steinberg C, Champagne J, Deyell MW, Dubuc M, ... Andrade JG, CIRCA-DOSE Study Investigators
Background
Early recurrence of atrial tachyarrhythmia (ERAT) is common after pulmonary vein isolation (PVI) and has been associated with an increased risk of late atrial fibrillation (AF) recurrence.
Objective
The purpose of this study was to determine the incidence and outcomes of patients experiencing ERAT after PVI using advanced-generation ablation technologies.
Methods
This is a prespecified substudy of the CIRCA-DOSE (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double-Short vs Standard Exposure Duration) trial, a prospective, randomized, multicenter study comparing PVI with contact force-guided radiofrequency ablation to secondary-generation cryoballoon ablation for paroxysmal AF. All study patients received an implantable cardiac monitor to allow continuous rhythm monitoring. ERAT was defined as any recurrent atrial tachyarrhythmia within the first 90 days after AF ablation.
Results
ERAT occurred in 61% of the 346 patients at a median of 12 days (range 1-90 days) after ablation. ERAF was a significant predictor of late recurrence (60.1% with ER vs 25.9% without ER; P <.001) and symptomatic atrial tachyarrhythmia (31.6% with ERAF vs 6.7% without ERAF; P <.001). Receiver operating curve analyses revealed a strong correlation between ERAT timing and burden and late recurrence. Multivariate analysis identified ER timing (hazard ratio [HR] 2.90; 95% confidence interval [CI] 1.41-5.95; P = .004) and burden (HR 1.05 per 1% ER burden; 95% CI 1.04-1.07; P <.001) as strong independent predictors of late recurrence. Incidence rate, timing, burden, and prognostic significance of ER did not differ between the study groups.
Conclusion
ERAT remains common after PVI despite use of advanced-generation ablation technologies. Early AF recurrence beyond 3 weeks after ablation is associated with increased risk of late recurrence.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 11 Jun 2021; epub ahead of print
Steinberg C, Champagne J, Deyell MW, Dubuc M, ... Andrade JG, CIRCA-DOSE Study Investigators
Heart Rhythm: 11 Jun 2021; epub ahead of print | PMID: 34126269
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Impact:
Abstract

Accessory pathway ablation in Ebstein anomaly: A challenging substrate.

El-Assaad I, DeWitt ES, Mah DY, Gauvreau K, ... Triedman JK, Walsh EP
Background
Catheter ablation of accessory pathways (APs) in Ebstein anomaly (EA) has been associated with a high recurrence risk.
Objective
The purpose of this study was to compare outcomes of AP ablation in EA in an early (1990-2004) vs a recent (2005-2019) era and identify variables associated with recurrence.
Methods
A retrospective review of all catheter ablations for supraventricular tachycardia in EA at our institution was performed.
Results
We identified 76 patients with median (25th-75th quartiles) age 9 (2.6-13.3) years. Of these patients, 52 had AP alone, 12 had atrial flutter, 3 had atrioventricular nodal reentrant tachycardia, and 9 had AP plus at least 1 additional arrhythmia. Of the 61 patients with APs, a total of 78 separate APs were identified: 40 right-sided, 37 septal, and 1 left-sided. Acute success for AP first procedure was 89% and did not differ between early and recent eras (89% vs 88%; P = .48). However, 19 patients (31%) required repeat procedures (average 1.4 per patient) due to AP recurrence or ablation failure at first attempt. In comparison to early era, recent era ablations had significantly lower recurrence rates at 1 year (62% vs 19%; P = .005). At median follow-up of 2.5 (0.2-7) years, ultimate AP elimination after all procedures was 93%. Younger age at time of electrophysiological study (<2 vs 12-47 years: hazard ratio [HR] 7.3; P = .003) and ablation era (early era vs recent era: HR 3.65; P = .009) predicted recurrence.
Conclusion
Outcomes for AP ablation in patients with EA have improved, but there is still a relatedly high recurrence risk requiring repeat procedures.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 11 Jun 2021; epub ahead of print
El-Assaad I, DeWitt ES, Mah DY, Gauvreau K, ... Triedman JK, Walsh EP
Heart Rhythm: 11 Jun 2021; epub ahead of print | PMID: 34126268
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Impact:
Abstract

Right ventricular insertion promotes reinitiation of ventricular fibrillation in defibrillation failure.

Iijima K, Zhang H, Strachan MT, Huang J, Walcott GP, Rogers JM
Background
Shocks near defibrillation threshold (nDFT) strength commonly extinguish all ventricular fibrillation (VF) wavefronts, but a train of rapid, well-organized postshock activations (PAs) typically appears before sinus rhythm ensues. If one of the PA waves undergoes partial propagation block (wavebreak), reentry may be induced, causing VF to reinitiate and the shock to fail.
Objective
The purpose of this study was to determine whether wavebreak leading to VF reinititation following nDFT shocks occurs preferentially at the right ventricular insertion (RVI), which previous studies have identified as a key site for wavebreak.
Methods
We used panoramic optical mapping to image the ventricular epicardium of 6 isolated swine hearts during nDFT defibrillation episodes. After each experiment, the hearts were fixed and their geometry scanned with magnetic resonance imaging (MRI). The MRI and mapping datasets were spatially coregistered. For failed shocks, we identified the site of the first wavebreak of a PA wave during VF reinitiation.
Results
We recorded 59 nDFT failures. In 31 of these, the first wavebreak event occurred within 1 cm of the RVI centerline, most commonly on the anterior side of the right ventricular insertion (aRVI) (23/31). The aRVI region occupies 16.8% ± 2.5% of the epicardial surface and would be expected to account for only 10 wavebreaks if they were uniformly distributed. By χ2 analysis, aRVI wavebreaks were significantly overrepresented.
Conclusion
The anterior RVI is a key site in promoting nDFT failure. Targeting this site to prevent wavebreak could convert defibrillation failure to success and improve defibrillation efficacy.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:995-1003
Iijima K, Zhang H, Strachan MT, Huang J, Walcott GP, Rogers JM
Heart Rhythm: 30 May 2021; 18:995-1003 | PMID: 33508518
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Impact:
Abstract

Evolution of risk stratification and sudden death prevention in hypertrophic cardiomyopathy: Twenty years with the implantable cardioverter-defibrillator.

Maron BJ, Rowin EJ, Maron MS
Hypertrophic cardiomyopathy (HCM) is a relatively common inherited myocardial disorder, once regarded as largely untreatable with ominous prognosis and most visibly as a common cause of sudden death (SD) in the young. Over the last several years, HCM has been transformed into a contemporary treatable disease with management options that significantly alter clinical course. With the use of implantable cardioverter-defibrillators (ICDs) in the HCM patient population, a new paradigm has emerged, with primary prevention device therapy reliably terminating potentially lethal ventricular tachyarrhythmias (3%-4% per year) and being largely responsible for a >10-fold decrease in disease-related mortality (to 0.5% per year), independent of age. An evidenced-based and guideline directed clinical risk stratification algorithm has evolved, including variables identified with cardiac magnetic resonance. One or more risk markers judged major and relevant within a patient\'s clinical profile can be considered sufficient to recommend a primary prevention implant (associated with a measure of physician judgment and shared decision-making). ICD decisions using the prospective individual risk marker strategy have been associated with 95% sensitivity for identifying patients who subsequently experienced appropriate ICD therapy, (albeit often delayed substantially for >5 or >10 years after implant), but without heart failure deterioration or HCM death following device intervention. A rigid mathematically derived statistical risk model proposed by the European Society of Cardiology is associated with low sensitivity (ie, 33%) for predicting SD events.
Introduction:
of prophylactically inserted ICDs to HCM 20 years ago has significantly altered the clinical course and landscape of this disease. SD prevention has reduced HCM mortality significantly, making preservation of life and the potential for normal longevity a reality for most patients.


Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:1012-1023
Maron BJ, Rowin EJ, Maron MS
Heart Rhythm: 30 May 2021; 18:1012-1023 | PMID: 33508516
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Impact:
Abstract

Extent of peri-infarct scar on late gadolinium enhancement cardiac magnetic resonance imaging and outcome in patients with ischemic cardiomyopathy.

Tülümen E, Rudic B, Ringlage H, Hohneck A, ... Borggrefe M, Papavassiliu T
Background
Only a minority of patients who receive an implantable cardioverter-defibrillator (ICD) on the basis of left ventricular ejection fraction receive appropriate ICD therapy. Peri-infarct scar zone assessed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is a possible substrate for ventricular tachyarrhytmias (VTAs).
Objective
The aim of our prospective study was to determine whether LGE-CMR parameters can predict the occurrence of VTA in patients with ischemic cardiomyopathy (ICM).
Methods
Two hundred sixteen patients with ICM underwent CMR imaging before primary or secondary ICD implantation and were prospectively followed. We assessed CMR indices and CMR scar characteristics (infarct core and peri-infarct zone) to predict outcome and VTAs.
Results
Patients were followed up for 1497 days (interquartile range 697-2237 days). Forty-seven patients (21%) received appropriate therapy during follow-up. Patients with appropriate ICD therapy had smaller core scar (31.5% ± 8.5% vs 36.8% ± 8.9%; P = .0004) but larger peri-infarct scar (12.4% ± 2.6% vs 10.5% ± 2.9%; P = .0001) than did patients without appropriate therapy. In multivariate Cox regression analysis, peri-infarct scar (hazard ratio 1.15; 95% confidence interval 1.07-1.24; P = .0001) was independently and significantly associated with VTAs whereas left ventricular ejection fraction, right ventricular ejection fraction, core scar, and left atrial ejection fraction were not.
Conclusion
Scar extent of peri-infarct border zone was significantly associated with appropriate ICD therapy. Thus, LGE-CMR parameters can identify a subgroup of patients with ICM and an increased risk of life-threatening VTAs.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:954-961
Tülümen E, Rudic B, Ringlage H, Hohneck A, ... Borggrefe M, Papavassiliu T
Heart Rhythm: 30 May 2021; 18:954-961 | PMID: 33515714
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Impact:
Abstract

Racial differences in the incidence of atrial fibrillation after cryptogenic stroke.

Laslett DB, Haddad A, Mangrolia H, Gaballa D, ... Cooper JM, Whitman IR
Background
The incidence of atrial fibrillation (AF) is lower in nonwhites than in whites despite a higher burden of AF risk factors. However, the incidence of new AF after cryptogenic stroke in minorities is unknown.
Objective
The purpose of this study was to determine the incidence of AF after cryptogenic stroke in different racial/ethnic groups.
Methods
We retrospectively analyzed 416 consecutive patients undergoing insertable cardiac monitor implantation at our hospital from 2014 through 2019. Incidence of AF was identified through the review of device monitoring, including adjudication of AF episodes for accuracy, and compared by race.
Results
The mean follow-up time was 1.5 ± 1.1 years. The predominantly nonwhite cohort included 244 (59%) blacks and 109 (26%) Hispanics, and 45% (n=189) were male. The mean age was 62 ± 12 years; Blacks and Hispanics had more hypertension, diabetes, and chronic kidney disease and higher body mass index than did whites. In blacks and Hispanics, the cumulative incidences of AF at 1, 2, and 3 years were 14.1%, 19.9%, and 24% and 12.9%, 18.3%, and 20.9%, respectively. By comparison, the incidence in whites was significantly higher: 20.8%, 34.3%, and 40.3%. In a Cox proportional hazards model adjusting for common AF risk factors, blacks (hazard ratio 0.49; confidence interval 0.26-0.82; P = .03) and Hispanics (hazard ratio 0.39; confidence interval 0.18-0.83; P = .01) were less likely to have incident AF than whites.
Conclusion
In patients with an insertable cardiac monitor after cryptogenic stroke, the incidence of newly detected AF is approximately double in whites compared with both blacks and Hispanics. This has important implications for the investigation and treatment of nonwhites with cryptogenic stroke.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:847-852
Laslett DB, Haddad A, Mangrolia H, Gaballa D, ... Cooper JM, Whitman IR
Heart Rhythm: 30 May 2021; 18:847-852 | PMID: 33524625
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Impact:
Abstract

Spatial and transmural properties of the reentrant ventricular tachycardia circuit in arrhythmogenic right ventricular cardiomyopathy: Simultaneous epicardial and endocardial recordings.

Jiang R, Nishimura T, Beaser AD, Aziz ZA, ... Wu S, Tung R
Background
While advances in the characterization of the structural substrate in arrhythmogenic right ventricular cardiomyopathy (ARVC) have been made, the ventricular tachycardia (VT) circuit remains incompletely described.
Objective
The purpose of this study was to delineate the reentrant VT circuit with simultaneous epicardial and endocardial mapping (SEEM) in ARVC.
Methods
Twenty-three consecutive patients with ARVC and VT underwent SEEM at 4 centers between 2014 and 2020. Retrospective analysis was performed on combined isochronal activation maps.
Results
Of the 30 VT circuits, 24 were delineated with SEEM (956 [341-1843] endocardial points and 1763 [882-3054] epicardial points). The apex and outflow tract rarely harbored VT circuits, with 50% distributed in the inferior wall and 43% in the free wall. The entire tachycardia cycle length was recorded from the epicardium in 71% of circuits. In all circuits, a large proportion of the tachycardia cycle length was recorded from the epicardium relative to the endocardium. Localized epicardial reentry was observed in 35% of patients (14 mm × 15 mm), which was associated with smaller endocardial low voltage area (39 cm2 vs 104 cm2; P = .002) and preserved right ventricular ejection fraction (35% vs 25%; P = .046) compared with those with larger circuit dimensions. Seventy percent of termination sites were achieved from the epicardium.
Conclusion
High-resolution recordings from both myocardial surfaces confirm a consistent predominance of epicardial participation during reentry in ARVC. Only the perivalvular inflow region of the \"triangle of dysplasia\" had a strong propensity to harbor VT circuits, with the greatest proportion located in the inferior wall. Localized epicardial reentry may be a manifestation of earlier stage disease with a relative paucity of endocardial substrate.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:916-925
Jiang R, Nishimura T, Beaser AD, Aziz ZA, ... Wu S, Tung R
Heart Rhythm: 30 May 2021; 18:916-925 | PMID: 33524624
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Impact:
Abstract

Assessment of patients presenting with life-threatening ventricular arrhythmias and suspected myocarditis: The key role of endomyocardial biopsy.

Narducci ML, La Rosa G, Pinnacchio G, Inzani F, ... Pelargonio G, Crea F
Background
Life-threatening ventricular tachyarrhythmias (VAs) represent a significant cause of death in myocarditis.
Objective
The purpose of this study was to identify predictors of sustained VAs in patients with myocarditis and ventricular phenotype diagnosed by workflow including endomyocardial biopsy (EMB) guided by 3D electroanatomic mapping (3D-EAM).
Methods
We prospectively enrolled patients with suspected myocarditis and VAs, undergoing cardiac magnetic resonance imaging, coronary angiography, 3D-EAM, and EMB guided by 3D-EAM. At follow-up, sustained VAs were detected by device interrogation and 24-hour electrocardiographic Holter monitoring.
Results
We enrolled 54 consecutive patients (mean age 41 ± 14 years; 32(59%) men) with normal ventricular function; left ventricular and right ventricular (RV) late gadolinium enhancement was present, respectively, in 21 (46%) and 6 (13%) of the 46 patients who underwent cardiac magnetic resonance. In 31 patients, the histological diagnosis was myocarditis, while in 14 patients, focal replacement myocardial fibrosis (FRMF); in 9 patients, specimens were inadequate (diagnostic yield of EMB 83%). 3D-EAM showed a larger endocardial scar area for both ventricles in myocarditis than in FRMF (RV bipolar mean scar area 22 ± 16 cm2 vs 3 ± 2 cm2; P = .02; left ventricular bipolar mean scar area 13 ± 5 cm2 vs 4 ± 2 cm2; P = .02, respectively). At a follow-up of 21 months, freedom from sustained VAs was 58% in myocarditis and 92% in FRMF (log-rank, P = .008). Histological diagnosis of myocarditis and RV endocardial scar were independent predictors of sustained VAs (P = .02 for both).
Conclusion
Our data highlight the need for 3D-EAM-guided EMB in apparently healthy young patients with suspected myocarditis and VAs.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:907-915
Narducci ML, La Rosa G, Pinnacchio G, Inzani F, ... Pelargonio G, Crea F
Heart Rhythm: 30 May 2021; 18:907-915 | PMID: 33516948
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Impact:
Abstract

Prognosis of patients with severe left ventricular dysfunction after transvenous lead extraction and the need for additional hemodynamic support in the perioperative period.

Nishii N, Nishimoto T, Mizuno T, Masuda T, ... Kasahara S, Ito H
Background
Transvenous lead extraction (TLE) is necessary because of system infection, lead malfunction, or system upgrade. Patients with severe left ventricular dysfunction (SLVD) undergoing TLE may be at a higher risk because hemodynamic parameters may change unfavorably during or after TLE; however, this has not yet been clarified.
Objective
The purpose of this study was to examine whether patients with SLVD undergoing TLE have higher mortality.
Methods
All patients who underwent TLE were stratified as follows: patients with ejection fraction ≤ 35% (SLVD group) and those with ejection fraction > 35% (non-SLVD group).
Results
We assessed the data of 200 patients [SLVD group, 36 (18%); non-SLVD group, 164 (82%)]). Brain natriuretic peptide level and cardiac resynchronization therapy rate were higher in the SLVD group than in the non-SLVD group. There were no significant between-group differences in major complications and clinical success rates. Patients with SLVD were more likely to require additional hemodynamic support, such as catecholamine infusion, temporary atrium-ventricle sequential pacing, and temporary cardiac resynchronization therapy pacing (27.8% vs 1.2%; P < .001). The survival rate was not significantly different between the groups at 30 days and 1 year after TLE (SLVD vs non-SLVD: 30 days: 97.2% vs 99.4%; P = .215; 1 year: 80.6% vs 91.5%; P = .053). Multivariate Cox regression analysis revealed log brain natriuretic peptide and serum hemoglobin levels as predictors for 1-year mortality.
Conclusion
The prognosis after TLE was comparable between patients with and without SLVD. However, additional hemodynamic support was often necessary for patients with SLVD.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:962-969
Nishii N, Nishimoto T, Mizuno T, Masuda T, ... Kasahara S, Ito H
Heart Rhythm: 30 May 2021; 18:962-969 | PMID: 33516947
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Impact:
Abstract

Temperature monitoring and temperature-driven irrigated radiofrequency energy titration do not prevent thermally induced esophageal lesions in pulmonary vein isolation: A randomized study controlled by esophagoscopy before and after catheter ablation.

Grosse Meininghaus D, Blembel K, Waniek C, Kruells-Muench J, ... Kleemann T, Geller JC
Background
Endoscopically detected esophageal lesions (EDELs) are common following pulmonary vein isolation (PVI) and may progress to atrioesophageal fistula (AEF).
Objective
The purpose of this study was to study (1) the benefit of luminal esophageal temperature (LET) monitoring and (2) the impact of esophagogastroduodenoscopy (EGD) in detecting EDEL and defining pre-existing lesions. The primary endpoint was the number of ablation-induced lesions.
Methods
Patients with atrial fibrillation were randomized to PVI with LET monitoring (LET[+]) or without LET monitoring (LET[-]). All patients underwent EGD before and after PVI. Ablation power at the left atrial (LA) posterior wall was limited to 25 W in all patients and was titrated to a minimum of 10 W guided by esophageal temperature in the LET[+] group.
Results
Eighty-six patients (age 67 ± 10 years; 57% male) were included (44 LET[+], 42 LET[-]). PVI was achieved in all, and additional linear LA lesions were done in 50%. Eight patients developed EDEL (6 LET[+], 2 LET[-]; P = NS). Whereas LET <41°C did not differentiate with regard to EDEL formation, temperature overshooting ≥42°C was associated with a higher risk for new EDEL. Two-thirds of patients showed incidental findings (esophagitis, gastric ulcer) on preprocedural EGD; 8 esophageal lesions were pre-existing. Four patients in the LET[+] group developed epistaxis following insertion of the probe.
Conclusion
Monitoring of LET does not prevent ablation-induced esophageal lesions. Patients without temperature surveillance were not at higher risk, but temperatures ≥42°C were associated with increased likelihood of mucosal lesions.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:926-934
Grosse Meininghaus D, Blembel K, Waniek C, Kruells-Muench J, ... Kleemann T, Geller JC
Heart Rhythm: 30 May 2021; 18:926-934 | PMID: 33561587
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Impact:
Abstract

Blood biomarkers to detect new-onset atrial fibrillation and cardioembolism in ischemic stroke patients.

Harpaz D, Bajpai R, Ng GJL, Soljak M, ... Tok AIY, Seet RCS
Background
Accumulating data suggest blood biomarkers could inform stroke etiology.
Objective
The purpose of this study was to investigate the performance of multiple blood biomarkers in elucidating stroke etiology with a focus on new-onset atrial fibrillation (AF) and cardioembolism.
Methods
Between January and December 2017, information on clinical and laboratory parameters and stroke characteristics was prospectively collected from ischemic stroke patients recruited from the National University Hospital, Singapore. Multiple blood biomarkers (N-terminal pro-brain natriuretic peptide [NT-proBNP], d-dimer, S100β, neuron-specific enolase, vitamin D, cortisol, interleukin-6, insulin, uric acid, and albumin) were measured in plasma. These variables were compared with stroke etiology and the risk of new-onset AF and cardioembolism using multivariable regression methods.
Results
Of the 515 ischemic stroke patients (mean age 61 years; 71% men), 44 (8.5%) were diagnosed with new-onset AF, and 75 (14.5%) had cardioembolism. The combination of 2 laboratory parameters (total cholesterol ≤169 mg/dL; triglycerides ≤44.5 mg/dL) and 3 biomarkers (NT-proBNP ≥294 pg/mL; S100β ≥64 pg/mL; cortisol ≥471 nmol/l) identified patients with new-onset AF (negative predictive value [NPV] 90%; positive predictive value [PPV] 73%; area under curve [AUC] 85%). The combination of 2 laboratory parameters (total cholesterol ≤169 mg/dL; triglycerides ≤44.5 mg/dL) and 2 biomarkers (NT-proBNP ≥507 pg/mL; S100β ≥65 pg/mL) identified those with cardioembolism (NPV 86%; PPV 78%; AUC 87%). Adding clinical predictors did not improve the performance of these models.
Conclusion
Blood biomarkers could identify patients with increased likelihood of cardioembolism and direct the search for occult AF.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:855-861
Harpaz D, Bajpai R, Ng GJL, Soljak M, ... Tok AIY, Seet RCS
Heart Rhythm: 30 May 2021; 18:855-861 | PMID: 33561586
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Impact:
Abstract

Benefits of routine prophylactic femoral access during transvenous lead extraction.

Chung DU, Müller L, Ubben T, Yildirim Y, ... Pecha S, Hakmi S
Background
The number of patients requiring lead extraction has been increasing in recent years. Despite significant advances in operator experience and technique, unexpected complications may occur. Prophylactic placement of femoral sheaths allows for immediate endovascular access for emergency procedures and may shorten response time in the event of complications.
Objective
The purpose of this study was to assess the benefits of routine prophylactic femoral access in patients undergoing transvenous lead extraction (TLE) and to evaluate the methods, frequency, and efficacy of the emergency measures used in those patients.
Methods
We conducted a retrospective analysis of patients who underwent TLE from January 2012 to February 2019. The data were analyzed with regard to procedural complications and deployment of emergency measures via femoral access.
Results
Two hundred eighty-five patients (mean age 65.3 ± 15.5 years) were included in the study. Median lead dwell time was 84 months (interquartile range 58-144). Overall complication rate was 4.2% (n = 12), with 1.8% major complications (n = 5). Clinical success rate was 97.2%. Procedure-related mortality was 1.1% (n = 3). Femoral sheaths were actively engaged in 9.1% (n = 26) of cases. Deployment of snares was the most common intervention (n = 10), followed by prophylactic (n = 6) or emergency placement (n = 1) of occlusion balloons, temporary pacing (n = 3), venous angioplasty (n = 3), diagnostic venography (n = 3), and extracorporeal membrane oxygenation (n = 1). We did not observe any femoral vascular complications due to prophylactic sheath placement.
Conclusion
Routine prophylactic placement of femoral sheaths shortens response time and quickly establishes control in the event of various complications that may occur during TLE procedures.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:970-976
Chung DU, Müller L, Ubben T, Yildirim Y, ... Pecha S, Hakmi S
Heart Rhythm: 30 May 2021; 18:970-976 | PMID: 33577972
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Impact:
Abstract

Racial disparities in the utilization and in-hospital outcomes of percutaneous left atrial appendage closure among patients with atrial fibrillation.

Vincent L, Grant J, Ebner B, Potchileev I, ... Colombo R, de Marchena E
Background
Select patients with atrial fibrillation and contraindication to anticoagulation may benefit from percutaneous left atrial appendage closure (pLAAC).
Objective
The purpose of this study was to evaluate racial disparities in the nationwide utilization and outcomes of pLAAC.
Methods
We identified 16,830 hospitalizations for pLAAC between 2015 and 2017 using the National Inpatient Sample. Baseline characteristics, in-hospital mortality, complications, length of stay, and discharge disposition were assessed between White and Black/African American (AA) populations.
Results
Black/AA patients represented 4.1% of nationwide pLAAC recipients and were younger, more likely to be female, and had greater prevalence of hypertension, heart failure, hyperlipidemia, obesity, chronic kidney disease, and prior stroke history (P <.001 for all). Black/AA patients had significantly increased length of stay and nonroutine discharge (P <.001 for both) but comparable in-hospital mortality to White patients. Black/AA patients suffered from greater postoperative stroke (0.7% vs 0.2%), acute kidney injury (4.5% vs 2.1%), bleeding requiring transfusion (4.5% vs 1.4%), and venous thromboembolism (0.7% vs 0.1%; P <.01 for all). After controlling for possible confounding factors, Black/AA race was independently associated with significantly increased odds of bleeding requiring blood transfusion, stroke, venous thromboembolism, and nonroutine discharge.
Conclusion
Among pLAAC recipients nationwide, Black/AA populations were underrepresented and had greater complication rates, length of stay, and discharge complexity. This study highlights the importance of addressing ongoing racial disparities in both utilization and outcomes of pLAAC.

Published by Elsevier Inc.

Heart Rhythm: 30 May 2021; 18:987-994
Vincent L, Grant J, Ebner B, Potchileev I, ... Colombo R, de Marchena E
Heart Rhythm: 30 May 2021; 18:987-994 | PMID: 33588068
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Impact:
Abstract

Catheter ablation of ventricular tachycardia in ischemic cardiomyopathy: Impact of concomitant amiodarone therapy on short- and long-term clinical outcomes.

Di Biase L, Romero J, Du X, Mohanty S, ... Chen M, Natale A
Background
Substrate catheter ablation of scar-related ventricular tachycardia (VT) is a widely accepted therapeutic option for patients with ischemic cardiomyopathy (ICM).
Objective
The purpose of this study was to investigate whether concomitant amiodarone therapy affects procedural outcomes.
Methods
A total of 134 consecutive patients (89% male; age 66 ± 10 years) with ICM undergoing catheter ablation of VT were included in the study. Patients were sorted by amiodarone therapy before ablation. In all patients, a substrate-based catheter ablation (endocardial ± epicardial) in sinus rhythm abolishing all \"abnormal\" electrograms within the scar was performed. The endpoint of the procedure was VT noninducibility. After the ablation procedure, all antiarrhythmic medications were discontinued. All patients had an implantable cardioverter-defibrillator, and recurrences were analyzed through the device.
Results
In 84 patients (63%), the ablation was performed on amiodarone; the remaining 50 patients (37%) were off amiodarone. Patients had comparable baseline characteristics. Mean scar size area was 143.6 ± 44.9 cm2 on amiodarone vs 139.2 ± 36.8 cm2 off amiodarone (P = .56). More radiofrequency time was necessary to achieve noninducibility in the off-amiodarone group compared to the on-amiodarone group (68.1 ± 20.1 minutes vs 51.5 ± 19.7 minutes; P <.001). In addition, due to persistent VT inducibility, more patients in the off-amiodarone group required epicardial ablation than in the on-amiodarone group (13/50 [26%] vs 5/84 [6%], respectively; P <.001). During mean follow-up of 23.9 ± 11.6 months, recurrence of any ventricular arrhythmias off antiarrhythmic drugs was 44% (37/84) in the on-amiodarone group vs 22% (11/50) in the off-amiodarone group (P = .013).
Conclusion
Albeit, VT noninducibility after substrate catheter ablation for scar related VT was achieved faster, with less radiofrequency time and less need for epicardial ablation in patients taking amiodarone, these patients had significantly higher VT recurrence at long-term follow-up when this medication was discontinued.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:885-893
Di Biase L, Romero J, Du X, Mohanty S, ... Chen M, Natale A
Heart Rhythm: 30 May 2021; 18:885-893 | PMID: 33592323
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Impact:
Abstract

Optimizing lead placement for pacing in dyssynchronous heart failure: The patient in the lead.

Wouters PC, Vernooy K, Cramer MJ, Prinzen FW, Meine M
Cardiac resynchronization therapy (CRT) greatly reduces morbidity and mortality in patients with dyssynchronous heart failure. However, despite tremendous efforts, response has been variable and can be further improved. Although optimizing left ventricular lead placement (LVLP) is arguably the cornerstone of CRT, the procedure of LVLP using the transvenous approach has remained largely unchanged for more than 2 decades. Improvements have been developed using scar location and electrical and/or mechanical mapping, and interest in conduction system pacing as an alternative to biventricular pacing has emerged recently. Conduction system pacing is promising but may not be suitable for all patients with dyssynchronous heart failure. This review underscores the importance of a patient-tailored approach and discusses the potential applications of both conduction system pacing and targeted biventricular CRT.

Copyright © 2021 Elsevier Ltd. All rights reserved.

Heart Rhythm: 30 May 2021; 18:1024-1032
Wouters PC, Vernooy K, Cramer MJ, Prinzen FW, Meine M
Heart Rhythm: 30 May 2021; 18:1024-1032 | PMID: 33601035
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Impact:
Abstract

Does pulsed field ablation regress over time? A quantitative temporal analysis of pulmonary vein isolation.

Kawamura I, Neuzil P, Shivamurthy P, Petru J, ... Koruth JS, Reddy VY
Background
The tissue specificity of pulsed field ablation (PFA) makes it an attractive energy source for pulmonary vein (PV) isolation (PVI). However, beyond each PFA lesion\'s zone of irreversible electroporation and cell death, there may be a surrounding zone of reversible electroporation and cell injury that could potentially normalize with time.
Objective
The purpose of this study was to assess whether the level of electrical PVI that is observed acutely after PFA regresses over time.
Methods
In a clinical trial, patients with paroxysmal atrial fibrillation underwent PVI using a biphasic PFA waveform delivered through a dedicated, variably deployable multielectrode basket/flower catheter. Detailed voltage maps were created using a multispline diagnostic catheter immediately after PFA and again ∼3 months later in a prospective, protocol-specified reassessment procedure. We analyzed 20 patients who underwent PFA with durable PVI and available maps from both time points. To compare the ablated zones, the left- and right-sided PV antral isolation areas and nonablated posterior wall area were quantified and the distances between left and right PV low-voltage edges were measured.
Results
A comparison of voltage maps immediately after PFA and at a median of 84 days (interquartile range 69-90 days) later revealed that there was no significant difference in either the left- and right-sided PV antral isolation areas or nonablated posterior wall area. The distances between low-voltage edges on the posterior wall were also not significantly different between the 2 time points.
Conclusion
This study demonstrates that the level of PV antral isolation after PFA with a multielectrode PFA catheter persists without regression.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:878-884
Kawamura I, Neuzil P, Shivamurthy P, Petru J, ... Koruth JS, Reddy VY
Heart Rhythm: 30 May 2021; 18:878-884 | PMID: 33647464
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Impact:
Abstract

Absence of (sub-)acute cerebral events or lesions after electroporation ablation in the left-sided canine heart.

Neven K, Füting A, Byrd I, Heil RW, ... Donskoy E, Jensen JA
Background
Irreversible electroporation (IRE) is a nonthermal ablation modality. A 200-J application can create deep myocardial lesions, but gas bubbles are created at the ablation electrode. Cerebral effects of these bubbles are unknown.
Objective
The purpose of this study was to investigate gas microemboli-induced brain lesions after IRE and radiofrequency (RF) ablation to the left side of the canine heart, using magnetic resonance imaging (MRI) and histopathology.
Methods
In 11 canines, baseline cerebral MRI scans were performed. In 9 animals, after retrograde femoral artery access, 12 ± 4 200-J IRE applications were administered in the ascending aorta. In 2 animals, 30 minutes of irrigated 30-W RF ablation using 10-30g of contact force was applied in the left ventricle. At days 1 and 5 after ablation, MRI was repeated. The brain tissue then was histopathologically examined.
Results
All ablations and follow-up were uneventful. Intracardiac echography confirmed gas bubble formation after each IRE application. Neurologic examination was normal. MRI scans were normal in all animals at day 1 and were normal in 10 of 11 animals at day 5. In 1 animal, a single <2-mm-diameter lesion in the right temporal region could not be excluded as a small infarct or early hemorrhagic site. Histopathologic analysis of the same region showed no pathologic changes. In all other animals, gross and microscopic pathology were normal.
Conclusion
MRI images alone or in combination with histologic follow-up did not reveal treatment-related embolic events. Gross and microscopic pathology did not reveal evidence of treatment-related embolic events. IRE seems to be a safe ablation modality for the brain.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:1004-1011
Neven K, Füting A, Byrd I, Heil RW, ... Donskoy E, Jensen JA
Heart Rhythm: 30 May 2021; 18:1004-1011 | PMID: 33617997
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Impact:
Abstract

Individualized ablation strategy to treat persistent atrial fibrillation: Core-to-boundary approach guided by charge-density mapping.

Shi R, Chen Z, Pope MTB, Zaman JAB, ... Betts TR, Wong T
Background
Noncontact charge-density mapping allows rapid real-time global mapping of atrial fibrillation (AF), offering the opportunity for a personalized ablation strategy.
Objective
The purpose of this study was to compare the 2-year outcome of an individualized strategy consisting of pulmonary vein isolation (PVI) plus core-to-boundary ablation (targeting the conduction pattern core with an extension to the nearest nonconducting boundary) guided by charge-density mapping, with an empirical PVI plus posterior wall electrical isolation (PWI) strategy.
Methods
Forty patients (age 62 ± 12 years; 29 male) with persistent AF (10 ± 5 months) prospectively underwent charge-density mapping-guided PVI, followed by core-to-boundary stepwise ablation until termination of AF or depletion of identified cores. Freedom from AF/atrial tachycardia (AT) at 24 months was compared with a propensity score-matched control group of 80 patients with empirical PVI + PWI guided by conventional contact mapping.
Results
Acute AF termination occurred in 8 of 40 patients after charge-density mapping-guided PVI alone and in 21 of the remaining 32 patients after core-to-boundary ablation in the study cohort, compared with 8 of 80 (10%) in the control cohort (P <.001). On average, 2.2 ± 0.6 cores were ablated post-PVI before acute AF termination. At 24 months, freedom from AF/AT after a single procedure was 68% in the study group vs 46% in the control group (P = .043).
Conclusion
An individualized ablation strategy consisting of PVI plus core-to-boundary ablation guided by noncontact charge-density mapping is a feasible and effective strategy for treating persistent AF, with a favorable 24-month outcome.

Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:862-870
Shi R, Chen Z, Pope MTB, Zaman JAB, ... Betts TR, Wong T
Heart Rhythm: 30 May 2021; 18:862-870 | PMID: 33610744
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Abstract

Ventricular tachycardia burden reduction after substrate ablation: Predictors of recurrence.

Quinto L, Sanchez-Somonte P, Alarcón F, Garre P, ... Mont L, Roca-Luque I
Background
Substrate-based ventricular tachycardia (VT) ablation is a first-line treatment in patients with structural cardiac disease and sustained VT refractory to medical therapy. Despite technological improvements and increased knowledge of VT substrate, recurrence still is frequent. Published data are lacking on the possible reduction in VT burden after ablation despite recurrence.
Objective
The purpose of this study was to assess VT burden reduction during long-term follow-up after substrate ablation and identify predictors of VT recurrence.
Methods
We analyzed 234 consecutive VT ablation procedures in 207 patients (age 63 ± 14.9 years; 92% male; ischemic heart disease in 65%) who underwent substrate ablation in a single center from 2013 to 2018.
Results
After follow-up of 3.14 ± 1.8 years, the VT recurrence rate was 41.4%. Overall, a 99.6% reduction in VT burden (median VT episodes per year: preprocedural 3.546 [1.347-13.951] vs postprocedural 0.001 [0-0.689]; P = .001) and a 96.3% decrease in implantable cardioverter-defibrillator (ICD) shocks (preprocedural 1.145 [0.118-4.467] vs postprocedural 0.042 [0-0.111] per year; P = .017) were observed. In the subgroup of patients who experienced VT recurrences, VT burden decreased by 69.2% (median VT episodes per year: preprocedural 2.876 [1.105-8.801] vs postprocedural 0.882 [0.505-2.283]; P <.001). Multivariable analysis showed persistence of late potentials (67% vs 19%; hazard ratio 3.18 [2.18-6.65]; P <.001) and lower left ventricular ejection fraction (EF) (30 [25-40] vs 39 [30-50]; P = .022) as predictors of VT recurrence.
Conclusion
Despite a high recurrence rate during long-term follow-up, substrate-based VT ablation is related to a large reduction in VT burden and a decrease in ICD therapies. Lower EF and persistence of late potentials are predictors of recurrence.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:896-904
Quinto L, Sanchez-Somonte P, Alarcón F, Garre P, ... Mont L, Roca-Luque I
Heart Rhythm: 30 May 2021; 18:896-904 | PMID: 33639298
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Impact:
Abstract

Oral anticoagulants in extremely-high-risk, very elderly (>90 years) patients with atrial fibrillation.

Chao TF, Chiang CE, Chan YH, Liao JN, ... Lip GYH, Chen SA
Background
The prevalence and incidence of atrial fibrillation (AF) increase with age. However, older patients often are denied oral anticoagulation (OAC), especially if they are \"very elderly\" (age ≥90 years) and perceived to be high risk for bleeding, for example, those with a history of intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), or chronic kidney disease.
Objective
The purpose of this study was to investigate the effectiveness and safety of OAC in this high-risk, very elderly group.
Methods
We used the Taiwan National Health Insurance Research Database to identify high-risk, very elderly subjects taking OAC, either warfarin or a non-vitamin K antagonist oral anticoagulant (NOAC), and compared them to non-OAC users for the composite net clinical endpoint of ischemic stroke, ICH, major bleeding, or mortality.
Results
We studied 7362 subjects (mean age 92.5 years), of whom 1737 were taking NOACs, 670 warfarin, and 4955 non-OACs. Compared to non-OACs, warfarin was associated with a higher risk of the composite endpoint (adjusted hazard ratio [aHR] 1.163; 95% confidence interval [CI] 1.052-1.287), whereas NOACs were associated with a lower risk (aHR 0.763; 95% CI 0.702-0.830). After propensity matching, NOACs were associated with a lower risk of events compared to non-OACs or warfarin, whereas warfarin had a similar risk compared to non-OACs.
Conclusion
Warfarin was associated with a similar or even higher risk of composite clinical outcomes compared to non-OACs. NOACs were associated with a lower risk of composite endpoint compared to warfarin or non-OACs, and their use still should be considered in these high-risk, very elderly AF patients.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:871-877
Chao TF, Chiang CE, Chan YH, Liao JN, ... Lip GYH, Chen SA
Heart Rhythm: 30 May 2021; 18:871-877 | PMID: 33640447
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Impact:
Abstract

Competing risks in patients with primary prevention implantable cardioverter-defibrillators: Global Electrical Heterogeneity and Clinical Outcomes study.

Waks JW, Haq KT, Tompkins C, Rogers AJ, ... Chugh SS, Tereshchenko LG
Background
Global electrical heterogeneity (GEH) is associated with sudden cardiac death in the general population. Its utility in patients with systolic heart failure who are candidates for primary prevention (PP) implantable cardioverter-defibrillators (ICDs) is unclear.
Objective
The purpose of this study was to investigate whether GEH is associated with sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies in patients with heart failure and PP ICDs.
Methods
We conducted a multicenter retrospective cohort study. GEH was measured by spatial ventricular gradient (SVG) direction (azimuth and elevation) and magnitude, QRS-T angle, and sum absolute QRST integral on preimplant 12-lead electrocardiograms. Survival analysis using cause-specific hazard functions compared the strength of associations with 2 competing outcomes: sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies and all-cause death without appropriate ICD therapies.
Results
We analyzed 2668 patients (mean age 63 ± 12 years; 624 (23%) female; 78% white; 43% nonischemic cardiomyopathy; left ventricular ejection fraction 28% ± 11% from 6 academic medical centers). After adjustment for demographic, clinical, device, and traditional electrocardiographic characteristics, SVG elevation (hazard ratio [HR] per 1SD 1.14; 95% confidence interval [CI] 1.04-1.25; P = .004), SVG azimuth (HR per 1SD 1.12; 95% CI 1.01-1.24; P = .039), SVG magnitude (HR per 1SD 0.75; 95% CI 0.66-0.85; P < .0001), and QRS-T angle (HR per 1SD 1.21; 95% CI 1.08-1.36; P = .001) were associated with appropriate ICD therapies. Sum absolute QRST integral had different associations in infarct-related cardiomyopathy (HR 1.29; 95% CI 1.04-1.60) and nonischemic cardiomyopathy (HR 0.78; 95% CI 0.62-0.96) (Pinteraction = .022).
Conclusion
In patients with PP ICDs, GEH is independently associated with appropriate ICD therapies. The SVG vector points in distinctly different directions in patients with 2 competing outcomes.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:977-986
Waks JW, Haq KT, Tompkins C, Rogers AJ, ... Chugh SS, Tereshchenko LG
Heart Rhythm: 30 May 2021; 18:977-986 | PMID: 33684549
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Impact:
Abstract

Physiology-based electrocardiographic criteria for left bundle branch capture.

Jastrzębski M, Kiełbasa G, Curila K, Moskal P, ... Rajzer M, Vijayaraman P
Background
During left bundle branch (LBB) area pacing, it is important to confirm that capture of the LBB, and not just capture of only adjacent left ventricular (LV) myocardium, has been achieved.
Objective
The purpose of this study was to establish electrocardiographic (ECG) criteria for LBB capture. We hypothesized that because LBB pacing results in physiological depolarization of the LV, then the native QRS can serve as a reference for diagnosis of LBB capture in the same patient.
Methods
Only patients with evidence of LBB capture (QRS morphology transition) were included. Several QRS characteristics were compared between the native rhythm and different types of LBB area capture.
Results
A total of 357 ECGs (124 patients) were analyzed: 118 with native rhythm, 124 with nonselective LBB capture, 69 with selective LBB capture, and 46 with LV septal capture. Our hypotheses that during LBB capture the paced V6 R-wave peak time (RWPT; measured from QRS onset) equals the native V6 RWPT and that the paced V6 RWPT (measured from the stimulus) equals the LBB potential to V6 R-wave peak interval were positively validated. Criteria based on these rules had sensitivity and specificity of 88.2%-98.0% and 85.7%-95.4%, respectively. Moreover, 100% specific V6 RWPT cutoff for LBB capture diagnosis in patients with narrow QRS/right bundle branch block was determined to be 74 ms.
Conclusion
We showed equivalency of LV activation times on ECG during native and paced LBB conduction. Therefore, if V6 RWPT is longer during pacing, this finding is indicative of lack of LBB capture.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:935-943
Jastrzębski M, Kiełbasa G, Curila K, Moskal P, ... Rajzer M, Vijayaraman P
Heart Rhythm: 30 May 2021; 18:935-943 | PMID: 33677102
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Impact:
Abstract

Relationship of paced left bundle branch pacing morphology with anatomic location and physiological outcomes.

Lin J, Hu Q, Chen K, Dai Y, ... Gold MR, Zhang S
Background
Left bundle branch pacing (LBBP) is an emerging physiological pacing modality. However, little is known about pacing at different locations on the left bundle branch (LBB).
Objective
The purpose of this study was to explore pacing and physiological characteristics associated with different LBBP locations.
Methods
The study included 68 consecutive patients with normal unpaced QRS duration and successful LBBP implantation. Patients were divided into 3 groups according to the paced QRS complex as left bundle branch trunk pacing (LBTP), left posterior fascicular pacing (LPFP), or left anterior fascicular pacing (LAFP). Electrocardiographic (ECG) characteristics, pacing parameters, and fluoroscopic localization were collected and analyzed.
Results
There were 17 (25.0%), 35 (51.5%), and 16 (23.5%) patients in the LBTP, LPFP, and LAFP groups, respectively. All subgroups had relatively narrow paced QRS complex (128.6 ± 9.1 ms vs 133.7 ± 11.2 ms vs 134.8 ± 9.6 ms; P = .170), fast left ventricular activation (70.4 ± 9.0 ms vs 70.6 ± 10.2 ms vs 71.0 ± 9.0 ms; P = .986), as well as low and stable pacing thresholds. Delayed right ventricular activation and interventricular dyssynchrony were similar between groups. Fluoroscopic imaging indicated that the lead tip was located most commonly in the basal-middle region of the septum (67.7%), and this was independent of paced QRS morphology group (88.2% vs 57.1% vs 68.8%; P = .106).
Conclusion
Pacing at different sites of the LBB resulted in similar intraventricular and interventricular electrical synchrony in patients with an intact conduction system. Fluoroscopic imaging alone could not predict specific LBBP paced ECG morphology.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; 18:946-953
Lin J, Hu Q, Chen K, Dai Y, ... Gold MR, Zhang S
Heart Rhythm: 30 May 2021; 18:946-953 | PMID: 33781981
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Impact:
Abstract

Late arrhythmias in patients with new-onset persistent left bundle branch block after transcatheter aortic valve replacement using a balloon-expandable valve.

Muntané-Carol G, Nombela-Franco L, Serra V, Urena M, ... Philippon F, Rodés-Cabau J
Background
The arrhythmic burden after discharge in patients with new-onset left bundle branch block (LBBB) undergoing transcatheter aortic valve replacement (TAVR) with the balloon-expandable SAPIEN 3 (S3) valve remains largely unknown.
Objective
The purpose of this study was to determine the incidence of late arrhythmias in patients with new-onset LBBB undergoing TAVR with the balloon-expandable S3 valve.
Methods
This was a multicenter, prospective study that included 104 consecutive TAVR patients with new-onset persistent LBBB following TAVR with the S3 valve. An implantable cardiac monitor (Reveal XT, Reveal LINQ) was implanted before discharge. The primary endpoint was the incidence of high-degree atrioventricular block or complete heart block (HAVB/CHB).
Results
A total of 40 patients (38.5%) had at least 1 significant arrhythmic event, leading to a treatment change in 17 (42.5%). Significant bradyarrhythmias occurred in 20 of 104 patients (19.2%) (34 HAVB/CHB episodes, 252 severe bradycardia episodes), with 10 of 20 patients (50%) exhibiting at least 1 episode of HAVB/CHB. Most HAVB/CHB episodes (60%) occurred within 4 weeks after discharge. Nine patients (8.7%) underwent permanent pacemaker implantation at 12 months based on the Reveal findings (6 HAVB/CHB, 3 severe bradycardia).
Conclusion
S3 valve recipients with new-onset LBBB have a high arrhythmic burden, with more than one-third of patients exhibiting at least 1 significant arrhythmic episode within 12 months (HAVB/CHB in 10% of patients). About one-half of bradyarrhythmic events occurred within 4 weeks after discharge. These results should inform future strategies on the use of continuous electrocardiographic monitoring in TAVR S3 patients with new conduction disturbances following the procedure.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 30 May 2021; epub ahead of print
Muntané-Carol G, Nombela-Franco L, Serra V, Urena M, ... Philippon F, Rodés-Cabau J
Heart Rhythm: 30 May 2021; epub ahead of print | PMID: 34082083
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Impact:
Abstract

Echocardiographic deformation imaging unmasks global and regional mechanical dysfunction in patients with idiopathic ventricular fibrillation: A multicenter case-control study.

Groeneveld SA, van der Ree MH, Taha K, de Bruin-Bon RHA, ... Postema PG, Hassink RJ
Background
Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with sudden onset of ventricular fibrillation of unidentified origin. New diagnostic tools that can detect subtle abnormalities are needed to diagnose and treat patients with an underlying substrate.
Objective
The purpose of this study was to explore echocardiographic deformation characteristics in IVF patients.
Methods
Echocardiograms were analyzed with deformation imaging by 2-dimensional speckle tracking. Global and regional measurements of the left ventricle (LV) and right ventricle (RV) were performed. Regional LV deformation patterns were evaluated for the presence of postsystolic shortening. Regional RV deformation patterns were classified as type I (normal) or type II/III (abnormal).
Results
In total, 47 IVF patients (mean age 45 years; left ventricular ejection fraction [LVEF] 56%) and 47 healthy controls (mean age 41 years; LVEF 60%) were included. IVF patients showed more global deformation abnormalities as indicated by lower LV global longitudinal strain (18.5% ± 2.6% vs 21.6% ± 1.8%; P <.001) and higher LV mechanical dispersion (41 ± 12 ms vs 26 ± 6 ms; P <.001). In addition, IVF patients showed more regional LV postsystolic shortening compared to healthy controls (50% vs 11%; P <.001). Abnormal RV deformation patterns were observed in 16% of IVF patients and in none of the control subjects (P <.001).
Conclusion
We were able to show both regional and global echocardiographic deformation abnormalities in IVF patients. This study provides evidence that localized myocardial disease is present in a subset of IVF patients.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 27 May 2021; epub ahead of print
Groeneveld SA, van der Ree MH, Taha K, de Bruin-Bon RHA, ... Postema PG, Hassink RJ
Heart Rhythm: 27 May 2021; epub ahead of print | PMID: 34058391
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Impact:
Abstract

Arrhythmia prevalence among patients with polymyositis-dermatomyositis in the United States: An observational study.

Naaraayan A, Meredith A, Nimkar A, Arora G, Bharati R, Acharya P
Background
Systemic inflammation has been associated with atherosclerotic cardiovascular diseases (ASCVD) and arrhythmia occurrence in rheumatologic conditions such as rheumatoid arthritis. Polymyositis and dermatomyositis (PD) are rare rheumatologic conditions characterized by symmetrical proximal muscle weakness and, in the case of dermatomyositis, cutaneous eruption. Although there is literature associating PD with ASCVD, no population-level studies have analyzed arrhythmia risk in PD.
Objective
The purpose of this study was to assess the prevalence of arrhythmia and its subtypes by age and sex in patients with PD and to determine associations between arrhythmia and PD.
Methods
This retrospective cohort study included adults for whom hospitalizations had been recorded in the National Inpatient Sample database in the United States between 2016 and 2018. Patients with PD were matched (1:10) by age to patients without PD. Prevalence of arrhythmia was calculated in the 2 groups and compared by sex and age groups. Associations between PD and arrhythmia were determined after adjustment for common arrhythmia risk factors.
Results
From 107,001,355 hospitalizations, 32,085 adults with PD were matched to 320,850 controls. Patients with PD aged <70 years had a higher prevalence of arrhythmia and higher adjusted odds of arrhythmia compared with controls. This increased risk was only seen for supraventricular arrhythmias. Adults with PD had increased odds of in-hospital mortality if they had an arrhythmia diagnosis (odds ratio 3.3; 95% confidence interval 2.5-4.5; P <.001).
Conclusion
We found a higher prevalence and odds of arrhythmias, particularly supraventricular arrhythmias, in young and middle-aged patients with PD compared with matched controls. Arrhythmias were associated with significant mortality among patients with PD.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 25 May 2021; epub ahead of print
Naaraayan A, Meredith A, Nimkar A, Arora G, Bharati R, Acharya P
Heart Rhythm: 25 May 2021; epub ahead of print | PMID: 34048962
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Impact:
Abstract

Predictors and outcomes of heart block during surgical stage I palliation of patients with a single ventricle: A report from the NPC-QIC.

Czosek RJ, Anderson JB, Baskar S, Khoury PR, Jayaram N, Spar DS
Background
Mortality in cohorts with a single ventricle remains high with multiple associated factors. The effect of heart block during stage I palliation remains unclear.
Objective
The purpose of this study was to study patient and surgical risks of heart block and its effect on 12-month transplant-free survival in patients with a single ventricle.
Methods
Patient, surgical, outcome data and heart block status (transient and permanent) were obtained from the National Pediatric Cardiology Quality Improvement Collaborative single ventricle database. Bivariate analysis was performed comparing patients with and without heart block, and multivariate modeling was used to identify variables associated with block. One-year outcomes were analyzed to identify variables associated with lower 12-month transplant-free survival.
Results
In total, 1423 patients were identified, of whom 28 (2%) developed heart block (second degree or complete) during their surgical admission. Associated risk factors for block included heterotaxy syndrome (odds ratio [OR] 6.4) and atrial flutter/fibrillation (OR 3.8). Patients with heart block had lower 12-month survival, though only in patients with complete heart block as opposed to second degree block. At 12 months of age, 43% (12/28) of patients with heart block died and were more likely to experience mortality at 12 months than patients without block (OR 4.9; 95% confidence interval 1.4-17.5; P = .01).
Conclusion
Although rare, complete heart block after stage I palliation represents an additional risk of poor outcomes in this high-risk patient population. Heterotaxy syndrome was the most significant risk factor for the development of heart block after stage I palliation. The role of transient block in outcomes and potential rescue with long-term pacing remains unknown and requires additional study.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 20 May 2021; epub ahead of print
Czosek RJ, Anderson JB, Baskar S, Khoury PR, Jayaram N, Spar DS
Heart Rhythm: 20 May 2021; epub ahead of print | PMID: 34029735
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Impact:
Abstract

Impact of a predefined pacemapping protocol use for ablation of infrequent premature ventricular complexes: A prospective, multicenter study.

Jáuregui B, Penela D, Fernández-Armenta J, Acosta J, ... Pedrote A, Berruezo A
Background
Pacemapping (PM) is a useful maneuver for aiding premature ventricular complex (PVC) ablation. Its standalone clinical value is still to be defined.
Objectives
The purpose of this study was to analyze the efficacy of a predefined PM protocol for low-burden PVC ablation, regardless of their site of origin (SOO) and the presence of structural heart disease.
Methods
This was a prospective, nonrandomized, multicenter study. The PM protocol was performed when <1 PVC/min was found. The \"target area\" was delimited by the 3 best matching points >94% correlation, and 3 radiofreqency (RF) applications were delivered.
Results
Of 185 patients, 105 (57%) underwent activation mapping, 60 (32%) were PM-guided, and 20 (11%) were canceled due to absence of PVCs. Baseline QRS, PVC burden, and outflow tract origin were independent predictors of PM-guided ablation. A higher proportion of right ventricular outflow tract SOO in the PM group (52% vs 40%; P = .03) was observed. Mean target area was 0.6 ± 0.9 cm2. Mean 10-ms isochronal area in local activation time (LAT)-guided procedures was higher (1.7 ± 2.3 cm2; P <.001). Mean number of PM matching points acquired was 39 ± 21 (range 6-98). Mean mapping and RF times were similar in both groups. However, significantly shorter procedural (53 ± 24 vs 61 ± 26 minutes; P = .04) as well as RF times (111 ± 51 vs 149 ± 149 seconds; P = .05) were needed in the PM group using the proposed protocol. Global clinical success reached 87% for the PM group and 90% (P = .58) the for LAT mapping group.
Conclusion
When LAT mapping is precluded, application of a PM-guided ablation protocol directed to >94% matching correlation target area is a more efficient alternative with comparable clinical results.

Copyright © 2021. Published by Elsevier Inc.

Heart Rhythm: 20 May 2021; epub ahead of print
Jáuregui B, Penela D, Fernández-Armenta J, Acosta J, ... Pedrote A, Berruezo A
Heart Rhythm: 20 May 2021; epub ahead of print | PMID: 34029733
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Impact:
Abstract

Tachypacing-induced CREB/CD44 signaling contributes to the suppression of L-type calcium channel expression and the development of atrial remodeling.

Chang SH, Chan YH, Chen WJ, Chang GJ, Lee JL, Yeh YH
Background
Atrial fibrillation (AF), a common arrhythmia in clinics, is characterized as downregulation of L-type calcium channel (LTCC) and shortening of atrial action potential duration (APD). Our prior studies have shown the association of CD44 with AF genesis.
Objective
The purpose of this study was to explore the potential role of CD44 and its related signaling in tachypacing-induced downregulation of LTCC.
Methods and results
In vitro, tachypacing in atrium-derived myocytes (HL-1 cell line) induced activation (phosphorylation) of cyclic adenosine monophosphate response element-binding protein (CREB). Furthermore, tachypacing promoted an association between CREB and CD44 in HL-1 myocytes, which was documented in atrial tissues from patients with AF. Deletion and mutational analysis of the LTCC promoter along with chromatin immunoprecipitation revealed that cyclic adenosine monophosphate response element is essential for tachypacing-inhibited LTCC transcription. Tachypacing also hindered the binding of p-CREB to the promoter of LTCC. Blockade of CREB/CD44 signaling in HL-1 cells attenuated tachypacing-triggered downregulation of LTCC and shortening of APD. Atrial myocytes isolated from CD44-/- mice exhibited higher LTCC current and longer APD than did those from wild-type mice. Ex vivo, tachypacing caused less activation of CREB in CD44-/- mice than in wild-type mice. In vivo, burst atrial pacing stimulated less inducibility of AF in CREB inhibitor-treated mice than in controls.
Conclusion
Tachypacing-induced CREB/CD44 signaling contributes to the suppression of LTCC, which provides valuable information about the pathogenesis of atrial modeling and AF.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 19 May 2021; epub ahead of print
Chang SH, Chan YH, Chen WJ, Chang GJ, Lee JL, Yeh YH
Heart Rhythm: 19 May 2021; epub ahead of print | PMID: 34023501
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Impact:
Abstract

Pericardial effusion requiring intervention in patients undergoing percutaneous left atrial appendage occlusion: Prevalence, predictors, and associated in-hospital adverse events from 17,700 procedures in the United States.

Munir MB, Khan MZ, Darden D, Pasupula DK, ... Reeves R, Hsu JC
Background
Left atrial appendage occlusion has shown promise in mitigating the risk of stroke in selected patients with atrial fibrillation.
Objective
The purpose of this study was to determine the real-world prevalence and in-hospital outcomes in left atrial appendage occlusion (Watchman) recipients complicated by pericardial effusion requiring percutaneous drainage or open cardiac surgery-based intervention.
Methods
Data were derived from the National Inpatient Sample database from January 2015 to December 2017. The primary outcomes assessed were the prevalence of pericardial effusion requiring intervention and in-hospital outcomes including mortality, other major complications, hospital stay > 1 day, and hospitalization costs. Predictors of pericardial effusion requiring intervention were also analyzed.
Results
Pericardial effusion requiring intervention occurred in 220 total patients (1.24%). After multivariable adjustment, pericardial effusion requiring intervention was associated with in-hospital mortality (adjusted odds ratio [aOR] 511.6; 95% confidence interval [CI] 122-2145.3), other Watchman-related major complications (aOR 1.35; 95% CI 0.83-2.19), length of stay > 1 day (aOR 17.64; 95% CI 12.56-24.77), and hospitalization cost above the median of $24,327 (aOR 3.58; 95% CI 2.61-4.91). Independent patient predictors of pericardial effusion requiring intervention from the procedure included advanced age (aOR 1.029 per 1-year increase; 95% CI 1.009-1.05 per 1-year increase), higher CHA2DS2-VASc score (aOR 1.221 per 1-point increase; 95% CI 1.083-1.377 per 1-point increase), and obesity (aOR 2.033; 95% CI 1.464-2.823).
Conclusion
In a large, contemporary real-world cohort of Watchman recipients in US practice, the prevalence of pericardial effusion requiring intervention was 1.24%. Pericardial effusion requiring intervention was associated with several adverse events including increased in-hospital mortality, other major complications, prolonged hospital stay, and hospitalization costs.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 17 May 2021; epub ahead of print
Munir MB, Khan MZ, Darden D, Pasupula DK, ... Reeves R, Hsu JC
Heart Rhythm: 17 May 2021; epub ahead of print | PMID: 34020049
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Impact:
Abstract

Postinfarct ventricular tachycardia substrate: Characterization and ablation of conduction channels using ripple mapping.

Katritsis G, Luther V, Jamil-Copley S, Koa-Wing M, ... Linton NWF, Kanagaratnam P
Background
Conduction channels have been demonstrated within the postinfarct scar and seem to be co-located with the isthmus of ventricular tachycardia (VT). Mapping the local scar potentials (SPs) that define the conduction channels is often hindered by large far-field electrograms generated by healthy myocardium.
Objective
The purpose of this study was to map conduction channel using ripple mapping to categorize SPs temporally and anatomically. We tested the hypothesis that ablation of early SPs would eliminate the latest SPs without direct ablation.
Methods
Ripple maps of postinfarct scar were collected using the PentaRay (Biosense Webster) during normal rhythm. Maps were reviewed in reverse, and clusters of SPs were color-coded on the geometry, by timing, into early, intermediate, late, and terminal. Ablation was delivered sequentially from clusters of early SPs, checking for loss of terminal SPs as the endpoint.
Results
The protocol was performed in 11 patients. Mean mapping time was 65 ± 23 minutes, and a mean 3050 ± 1839 points was collected. SP timing ranged from 98.1 ± 60.5 ms to 214.8 ± 89.8 ms post QRS peak. Earliest SPs were present at the border, occupying 16.4% of scar, whereas latest SPs occupied 4.8% at the opposing border or core. Analysis took 15 ± 10 minutes to locate channels and identify ablation targets. It was possible to eliminate latest SPs in all patients without direct ablation (mean ablation time 16.3 ± 11.1 minutes). No VT recurrence was recorded (mean follow-up 10.1 ± 7.4 months).
Conclusion
Conduction channels can be located using ripple mapping to analyze SPs. Ablation at channel entrances can eliminate the latest SPs and is associated with good medium-term results.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 14 May 2021; epub ahead of print
Katritsis G, Luther V, Jamil-Copley S, Koa-Wing M, ... Linton NWF, Kanagaratnam P
Heart Rhythm: 14 May 2021; epub ahead of print | PMID: 34004345
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Impact:
Abstract

In vitro modeling accurately predicts cardiac lead fracture at 10 years.

Wilkoff BL, Donnellan E, Himes A, Ben Johnson W, ... Lexcen DR, Crossley GH
Background
Development of a cardiac lead fracture model has the potential to differentiate well-performing lead designs from poor performing ones and could aid in future lead development.
Objective
The purpose of this study was to demonstrate a predictive model for lead fracture and validate the results generated by the model by comparing them to observed 10-year implantable cardioverter-defibrillator lead fracture-free survival.
Methods
The model presented here uses a combination of in vivo patient data, in vitro conductor fatigue test data, and statistical simulation to predict the fracture-free survival of cardiac leads. The model was validated by comparing the results to human clinical performance data from the Medtronic Sprint Fidelis (Minneapolis, MN) models 6931 (single coil, active fixation) and 6949 (dual coil, active fixation), as well as the Quattro model 6947 (dual coil, active fixation).
Results
Median patient age in the single coil Fidelis 6931 population (64 years) was less than in the dual coil Fidelis 6949 and Quattro populations (68 years). Modeled and observed fracture-free survival for Quattro (>97%) was superior to that for Fidelis (<94%). The modeled survival agreed with the observed fracture-free survival data. The average model error was 0.3% (SD 1.2%).
Conclusion
This model for cardiac lead fracture-free survival using in vivo lead bending measurements and in vitro bench testing can be used to predict lead performance as observed by alignment with field survival data.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 13 May 2021; epub ahead of print
Wilkoff BL, Donnellan E, Himes A, Ben Johnson W, ... Lexcen DR, Crossley GH
Heart Rhythm: 13 May 2021; epub ahead of print | PMID: 33992730
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Impact:
Abstract

Renal denervation prevents myocardial structural remodeling and arrhythmogenicity in a chronic kidney disease rabbit model.

Liu SH, Lo LW, Chou YH, Lin WL, ... Yamada S, Chen SA
Background
The electrophysiological (EP) effects and safety of renal artery denervation (RDN) in chronic kidney disease (CKD) are unclear.
Objective
The purpose of this study was to investigate the arrhythmogenicity of RDN in a rabbit model of CKD.
Methods
Eighteen New Zealand white rabbits were randomized to control (n = 6), CKD (n = 6), and CKD-RDN (n = 6) groups. A 5/6 nephrectomy was selected for the CKD model. RDN was applied in the CKD-RDN group. All rabbits underwent cardiac EP studies for evaluation. Immunohistochemistry, myocardial fibrosis, and renal catecholamine levels were evaluated.
Results
The CKD group (34.8% ± 9.2%) had a significantly higher ventricular arrhythmia (VA) inducibility than the control (8.6% ± 3.8%; P <.01) and CKD-RDN (19.5% ± 6.3%; P = .01) groups. In the CKD-RDN group, ventricular fibrosis was significantly decreased compared to the CKD group (7.4% ± 2.0 % vs 10.4% ± 3.7%; P = .02). Sympathetic innervation in the CKD group was significantly increased compared to the control and CKD-RDN groups [left ventricle: 4.1 ± 1.8 vs 0.8 ± 0.5 (102 μm2/mm2), P <.01; 4.1 ± 1.8 vs 0.9± 0.6 (102 μm2/mm2), P <.01; right ventricle: 3.6 ± 1.0 vs 1.0 ± 0.4 (102 μm2/mm2), P <.01; 3.6 ± 1.0 vs 1.0 ± 0.5 (102 μm2/mm2), P <.01].
Conclusion
Neuromodulation by RDN demonstrated protective effects with less structural and electrical remodeling, leading to attenuated VAs. In a rabbit model of CKD, RDN plays a therapeutic role by lowering the risk of VA caused by autonomic dysfunction.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 12 May 2021; epub ahead of print
Liu SH, Lo LW, Chou YH, Lin WL, ... Yamada S, Chen SA
Heart Rhythm: 12 May 2021; epub ahead of print | PMID: 33992732
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Impact:
Abstract

Interatrial septal tachycardias following atrial fibrillation ablation or cardiac surgery: Electrophysiological features and ablation outcomes.

Garg L, Pothineni NVK, Arroyo A, Rodriguez D, ... Saenz LC, Santangeli P
Background
Interatrial septal tachycardias (IAS-ATs) following atrial fibrillation (AF) ablation or cardiac surgery are rare, and their management is challenging.
Objective
The purpose of this study was to investigate the electrophysiological features and outcomes associated with catheter ablation of IAS-AT.
Methods
We screened 338 patients undergoing catheter ablation of ATs following AF ablation or cardiac surgery. Diagnosis of IAS-AT was based on activation mapping and analysis of response to atrial overdrive pacing.
Results
Twenty-nine patients (9%) had IAS-AT (cycle length [CL] 311 ± 104 ms); 16 (55%) had prior AF ablation procedures (median 3; range 1-5), 3 (10%) had prior surgical maze, and 12 (41%) had prior cardiac surgery (including atrial septal defect surgical repair in 5 and left atrial myxoma resection in 1). IAS substrate abnormalities were documented in all patients. Activation mapping always demonstrated a diffuse early IAS breakout with centrifugal biatrial activation, and atrial overdrive pacing showed a good postpacing interval (equal or within 25 ms of the AT CL) only at 1 or 2 anatomically opposite IAS sites in all cases. Ablation was acutely successful in 27 patients (93%) (from only the right IAS in 2, only the left IAS in 9, both IAS sides with sequential ablation in 13, and both IAS sides with bipolar ablation in 3). After median follow-up of 15 (6-52) months, 17 patients (59%) remained free from recurrent arrhythmias.
Conclusion
IAS-ATs are rare and typically occur in patients with evidence of IAS substrate abnormalities and prior cardiac surgery. Catheter ablation can be challenging and may require sequential unipolar ablation or bipolar ablation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 10 May 2021; epub ahead of print
Garg L, Pothineni NVK, Arroyo A, Rodriguez D, ... Saenz LC, Santangeli P
Heart Rhythm: 10 May 2021; epub ahead of print | PMID: 33984525
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Impact:
Abstract

Venous anatomy of the left ventricular summit: Therapeutic implications for ethanol infusion.

Tavares L, Fuentes S, Lador A, Da-Wariboko A, ... Dave AS, Valderrábano M
Background
Venous ethanol ablation (VEA) is effective for treatment of left ventricular (LV) summit (LVS) arrhythmias. The LVS venous anatomy is poorly understood and has inconsistent nomenclature.
Objective
The purpose of this study was to delineate the LVS venous anatomy by selective venography and 3-dimensional (3D) mapping during VEA and by venous-phase coronary computed tomographic angiography (vCTA).
Methods
We analyzed (1) LVS venograms and 3D maps of 53 patients undergoing VEA; and (2) 3D reconstructions of 52 vCTAs, tracing LVS veins.
Results
Angiography identified the following LVS veins: (1) LV annular branch of the great cardiac vein (GCV) (19/53); (2) septal (rightward) branches of the anterior ventricular vein (AIV) (53/53); and (3) diagonal branches of the AIV (51/53). Collateral connections between LVS veins and outflow, conus, and retroaortic veins were common. VEA was delivered to target arrhythmias in 38 of 53 septal, 6 of 53 annular, and 2 of 53 diagonal veins. vCTA identified LVS veins (range 1-5) in a similar distribution. GCV-AIV transition could either form an angle close to the left main artery bifurcation (n = 16; 88° ± 13°) or cut diagonally (n = 36; 133°±12°) (P ≤.001). Twenty-one patients had LV annular vein. In 28 patients only septal LVS veins were visualized in vCTA, in 2 patients only diagonal veins and in 22 patients both septal and diagonal veins were seen. In 39 patients the LVS veins reached the outflow tracts and their vicinity.
Conclusion
We provide a systematic atlas and nomenclature of LVS veins related to arrhythmogenic substrates. vCTA can be useful for noninvasive evaluation of LVS veins before ethanol ablation.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 10 May 2021; epub ahead of print
Tavares L, Fuentes S, Lador A, Da-Wariboko A, ... Dave AS, Valderrábano M
Heart Rhythm: 10 May 2021; epub ahead of print | PMID: 33989783
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Impact:
Abstract

P-wave signal-averaged electrocardiography: Reference values, clinical correlates, and heritability in the Framingham Heart Study.

Kornej J, Magnani JW, Preis SR, Soliman EZ, ... Benjamin EJ, Lin H
Background
P-wave signal-averaged electrocardiography (P-SAECG) quantifies atrial electrical activity. P-SAECG measures and their clinical correlates and heritability have had limited characterization in community-based cohorts.
Objective
The purpose of this study was to (1) establish reference values; (2) identify clinical risk factors associated with P-SAECG; and (3) estimate genetic heritability for P-SAECG traits.
Methods
We performed P-SAECG in 2 generations of Framingham Heart Study participants. We performed backward elimination regression models to assess associations of clinical factors with each SAECG trait (P-wave [PW] duration, root mean square voltage in terminal 40 ms [RMS40], terminal 30 ms RMS30, terminal 20 ms RMS20, RMS PW, and PW integral). We estimated the adjusted genetic heritability of P-SAECG measures using the Sequential Oligogenic Linkage Analysis Routines (SOLAR) program.
Results
We included 4307 participants (age 55 ± 14 years; 56% female). The reference values were derived from 1752 participants without cardiovascular risk factors. Median (2.5th percentile; 97.5th percentile) total PW duration was 118 ms (93; 146) in women and 128 ms (104; 158) in men in the reference sample, and 121 ms (94; 151) in women and 129 ms (103; 159) in the entire study cohort (broad sample). In the broad sample, after adjusting for age and sex, total PW duration was positively associated with height, weight, prevalent heart failure, history of atrial fibrillation (AF), and atrioventricular node blockers, and negatively associated with smoking, waist circumference, heart rate, and diabetes. The estimated heritability of P-SAECG traits was moderate, ranging from 11.9% for RMS30 to 24.9% for PW integral.
Conclusion
P-SAECG traits are associated with multiple AF-related risk factors and are moderately heritable.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 10 May 2021; epub ahead of print
Kornej J, Magnani JW, Preis SR, Soliman EZ, ... Benjamin EJ, Lin H
Heart Rhythm: 10 May 2021; epub ahead of print | PMID: 33989782
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Impact:
Abstract

Long-term survival following transvenous lead extraction: Importance of indication and comorbidities.

Mehta VS, Elliott MK, Sidhu BS, Gould J, ... Bosco P, Rinaldi CA
Background
Long-term outcomes are poorly understood, and data in patients undergoing transvenous lead extraction (TLE) are lacking.
Objective
The purpose of this study was to evaluate factors influencing survival in patients undergoing TLE depending on extraction indication.
Methods
Clinical data from consecutive patients undergoing TLE in the reference center between 2000 and 2019 were prospectively collected. The total cohort was divided into groups depending on whether there was an infective or noninfective indication for TLE. We evaluated the association of demographic, clinical, and device-related and procedure-related factors on mortality.
Results
A total of 1151 patients were included. Mean follow-up was 66 months, and mortality was 34.2% (n = 392). Of these patients, 632 (54.9%) and 519 (45.1%) were for infective and noninfective indications, respectively. A higher proportion in the infection group died (38.6% vs 28.5%; P <.001). In the total cohort, multivariable analysis demonstrated increased mortality risk with age >75 years (hazard ratio [HR] 2.98; 95% confidence interval [CI] 2.35-3.78; P <.001), estimated glomerular filtration rate <60 mL/min/1.73 m2 (HR 1.67; 95% CI 1.31-2.13; P <.001), higher cumulative comorbidity (HR 1.17; 95% CI 1.09-1.26; P <.001), reduced risk per percentage increase in left ventricular ejection fraction (HR 0.98; 95% CI 0.97-0.99; P <.001), and near unity per year of additional lead dwell time (HR 0.98; 95% CI 0.96-1.00; P = .037). Kaplan-Meier survival curves demonstrated worse prognosis, with a higher number of leads extracted and increasing comorbidities.
Conclusion
Long-term mortality for patients undergoing TLE remains high. Consensus guidelines recommend evaluating risk for major complications when determining whether to proceed with TLE. This study suggests also assessing longer-term outcomes when considering TLE in those with a high risk of medium- and long-term mortality, particularly for noninfective indications.

Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 09 May 2021; epub ahead of print
Mehta VS, Elliott MK, Sidhu BS, Gould J, ... Bosco P, Rinaldi CA
Heart Rhythm: 09 May 2021; epub ahead of print | PMID: 33984526
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Impact:
Abstract

Gain in real-world cardiac resynchronization therapy efficacy with SyncAV dynamic optimization: Heart failure hospitalizations and costs.

Varma N, Hu Y, Connolly AT, Thibault B, ... Nabutovsky Y, Zareba W
Background
SyncAV, a device-based cardiac resynchronization therapy (CRT) algorithm, promotes electrical optimization by dynamically adjusting atrioventricular intervals.
Objective
The purpose of this study was to evaluate the impact of SyncAV on heart failure hospitalizations (HFHs) and related costs in a real-world CRT cohort.
Methods
Patients with SyncAV-capable CRT devices followed by remote monitoring and enrolled in Medicare fee-for-service for at least 1 year preimplant and up to 2 years postimplant were studied. Patients with SyncAV OFF were 4:1 matched to those with SyncAV ON on preimplant HFH rate, demographics, comorbidities, disease etiology, and left bundle branch block. HFHs were determined from the primary diagnosis of inpatient hospitalizations, and the cost for each event was the sum of Medicare, supplemental insurance, and patient payment.
Results
After 4:1 propensity score matching, 3630 patients were studied (mean age 75 ± 8 years; 1386 [38%] female), including 726 (25%) patients with SyncAV ON. The pre-CRT HFH rate was 0.338 HFH events per patient-year. Overall, CRT diminished the HFH rate to 0.204 events per patient-year (P < .001). SyncAV elicited a larger reduction in HFH rate (SyncAV ON: hazard ratio [HR] 0.52; 95% confidence interval [CI] 0.41-0.66; P < .001 and SyncAV OFF: HR 0.68; 95% CI 0.59-0.77; P < .001). After 2 years, the HFH rate was lower in the SyncAV ON group than in the SyncAV OFF group (0.143 HFHs per patient-year vs 0.193 HFHs per patient-year; HR 0.70; 95% CI 0.55-0.89; P = .003) and fewer HFHs were followed by 30-day HFH readmissions (4.41% vs 7.68%; P = .003) and 30-day all-cause hospital readmissions (7.04% vs 10.01%; P = .010). The total 2-year HFH-associated costs per patient were lower with SyncAV ON (difference $1135; 90% CI $93-$2109; P = .038).
Conclusion
This large, real-world, propensity score-matched study demonstrates that SyncAV CRT is associated with significantly reduced HFHs and associated costs, incremental to standard CRT.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 06 May 2021; epub ahead of print
Varma N, Hu Y, Connolly AT, Thibault B, ... Nabutovsky Y, Zareba W
Heart Rhythm: 06 May 2021; epub ahead of print | PMID: 33965608
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Impact:
Abstract

Nationwide burden of sudden cardiac death: A study of 54,028 deaths in Denmark.

Lynge TH, Risgaard B, Banner J, Nielsen JL, ... Winkel BG, Tfelt-Hansen J
Background
A large proportion of all deaths are sudden cardiac deaths (SCDs). Reliable estimates of nationwide incidence of SCD, however, are missing.
Objectives
The goals of this study were to estimate SCD burden across all age groups in Denmark and to compare it with the estimates of other common causes of death.
Methods
All deaths in Denmark (population of 5.5 million) in 2010 were manually reviewed case by case. Autopsy reports, death certificates, and information from nationwide health registries were systematically examined to identify all SCD cases in 2010. According to the level of detail of the available information, all deaths were categorized as either non-SCD, definite SCD, probable SCD, or possible SCD.
Results
There were 54,028 deaths in Denmark in 2010, of which 6867 (13%) were categorized as SCD (591 (9%) definite SCD, 1568 (23%) probable SCD, and 4708 (68%) possible SCD). The incidence rate of definite SCD was 11 (95% confidence interval 10-12) per 100,000 person-years. Including definite, probable, and possible SCD cases, the highest possible overall SCD incidence rate was 124 (95% confidence interval 121-127) per 100,000 person-years. Estimated SCD burden was similar to or greater than the estimates of all other common causes of death. Of all SCD cases, 49% were not diagnosed with cardiovascular disease before death.
Conclusion
SCD accounted for up to 13% of all deaths. Almost half of all SCD cases occurred in persons without a history of cardiovascular disease. Consequently, the optimization of risk stratification and prevention of SCD in the general population should be given high priority.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 06 May 2021; epub ahead of print
Lynge TH, Risgaard B, Banner J, Nielsen JL, ... Winkel BG, Tfelt-Hansen J
Heart Rhythm: 06 May 2021; epub ahead of print | PMID: 33965606
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Impact:
Abstract

Double loop ventricular tachycardia activation patterns with single loop mechanisms: Asymmetric entrainment responses during \"pseudo-figure-of-eight\" reentry.

Nishimura T, Upadhyay GA, Aziz ZA, Beaser AD, ... Nayak HM, Tung R
Background
The classical paradigm of scar-related reentrant ventricular tachycardia (VT) features a circuit with a double loop figure-of-eight (F8) activation pattern.
Objective
The purpose of this study was to interrogate VT circuits with F8 activation patterns by entrainment mapping to differentiate an active loop from a passive loop.
Methods
Sixty VT circuits with >90% of tachycardia cycle length delineated in high resolution were retrospectively analyzed in 55 patients (nonischemic 49%). A pseudo-F8 VT circuit was defined as a double loop activation pattern driven by a single loop mechanism with a passive loop that yields a long postpacing interval (postpacing interval - tachycardia cycle length ≥ 30 ms).
Results
Single loop activation patterns were observed in 33% (n = 20). Of 40 circuits with F8 patterns by activation mapping, 20 were studied with entrainment mapping, where a passive loop was identified by a long postpacing interval in 50%. In 6 circuits where entrainment mapping was performed from both outer loop regions, all demonstrated asymmetric responses to entrainment, confirming a single loop mechanism. Entrainment from both lateral margins of the common pathway (n = 7) demonstrated an asymmetric response in 29%. In all pseudo-F8 circuits (n = 10), the shorter loop functioned as the active loop and ablation targeting the active loop side of the isthmus resulted in VT termination with a single radiofrequency application.
Conclusion
In a selected cohort, single loop mechanisms are more prevalent than double loop reentry in reentrant human VT. Half of VT circuits with double loop activation patterns can be demonstrated to be sustained by a single active loop mechanism by entrainment mapping. Ablation targeting the shorter active loop resulted in rapid termination during radiofrequency application.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 06 May 2021; epub ahead of print
Nishimura T, Upadhyay GA, Aziz ZA, Beaser AD, ... Nayak HM, Tung R
Heart Rhythm: 06 May 2021; epub ahead of print | PMID: 33965607
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Impact:
Abstract

A novel Ventricular map of Electrograms DUration as a Method to identify areas of slow conduction for ventricular tachycardia ablation: The VEDUM pilot study.

Rossi P, Cauti FM, Niscola M, Calore F, ... Iaia L, Bianchi S
Background
Bipolar electrogram (EGM) duration is indicative of local activation property and, if prolonged, is useful to discover areas of slow conduction favoring arrhythmias.
Objective
The present study aimed to create a map of EGM duration during the ventricular tachycardia (VT) (Ventricular Electrograms DUration as a Method map [VEDUM map]) to verify if the slowest activation area is crucial for reentry and could represent a suitable target for rapid VT interruption during ablation.
Methods
Prospectively 30 patients were enrolled for this study. Twenty-one patients were selected, and 24 VT maps with complete circuit delineation (>90% tachycardia cycle length) were analyzed. Activation and VEDUM maps during VT as well as voltage maps during sinus rhythm were created.
Results
Twenty-two of 24 VTs (88%) were interrupted during the first radiofrequency delivery (mean time 7.3 ± 5.4 seconds; range 3-25 seconds) at the area with the longest EGM duration (212 ± 47 ms; range 113-330 ms). The mean percentage of the cycle length of VT covered by the EGM with the longest duration was 58% ± 12%. In 9 patients (37%), the longest EGM was located at the isthmus entrance, at the exit in 7 maps (30%), and the mid-isthmuses in 8 maps (33%). In 6 patients (25%), the EGM covered the full diastolic phase. The mean isthmus width was 28 ± 11 mm (range 16-48 mm; median 25 mm).
Conclusion
A VEDUM map is highly accurate in defining a conductive vulnerable zone of the VT circuit. The longest EGM duration within the isthmus is highly predictive of rapid VT termination at the first radiofrequency delivery even in the case of large isthmuses.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 03 May 2021; epub ahead of print
Rossi P, Cauti FM, Niscola M, Calore F, ... Iaia L, Bianchi S
Heart Rhythm: 03 May 2021; epub ahead of print | PMID: 33957317
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Impact:
Abstract

The precordial R\' wave: A novel discriminator between cardiac sarcoidosis and arrhythmogenic right ventricular cardiomyopathy in patients presenting with ventricular tachycardia.

Hoogendoorn JC, Venlet J, Out YNJ, Man S, ... Stevenson WG, Zeppenfeld K
Background
Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease-specific RV activation patterns detectable on the 12-lead electrocardiogram. Dominant subepicardial scar in ARVC leads to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally (epsilon) waves with a small amplitude. Conversely, patchy transmural RV scar in CS may lead to conduction block and therefore late activated areas with preserved voltages reflected as preserved R\' waves.
Objective
The purpose of this study was to evaluate the distinct terminal activation patterns in precordial leads V1 through V3 as a discriminator between CS and ARVC.
Methods
Thirteen patients with CS affecting the RV and 23 patients with gene-positive ARVC referred for ventricular tachycardia ablation were retrospectively included in a multicenter approach. A non-ventricular-paced 12-lead surface electrocardiogram was analyzed for the presence and the surface area of the R\' wave (any positive deflection from baseline after an S wave) in leads V1 through V3.
Results
An R\' wave in leads V1 through V3 was present in all patients with CS compared to 11 (48%) patients with ARVC (P = .002). An algorithm including a PR interval of ≥220 ms, the presence of an R\' wave, and the surface area of the maximum R\' wave in leads V1 through V3 of ≥1.65 mm2 had 85% sensitivity and 96% specificity for diagnosing CS, validated in a second cohort (18 CS and 40 ARVC) with 83% sensitivity and 88% specificity.
Conclusion
An easily applicable algorithm including PR prolongation and the surface area of the maximum R\' wave in leads V1 through V3 of ≥1.65 mm2 distinguishes CS from ARVC. This QRS terminal activation in precordial leads V1 through V3 may reflect disease-specific scar patterns.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 02 May 2021; epub ahead of print
Hoogendoorn JC, Venlet J, Out YNJ, Man S, ... Stevenson WG, Zeppenfeld K
Heart Rhythm: 02 May 2021; epub ahead of print | PMID: 33957319
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Impact:
Abstract

Atrial arrhythmias and patient-reported outcomes in adults with congenital heart disease: An international study.

Casteigt B, Samuel M, Laplante L, Shohoudi A, ... Khairy P, of the APPROACH-IS Consortium and the International Society for Adult Congenital Heart Disease (ISACHD)
Background
Atrial arrhythmias (ie, intra-atrial reentrant tachycardia and atrial fibrillation) are a leading cause of morbidity and hospitalization in adults with congenital heart disease (CHD). Little is known about their effect on quality of life and other patient-reported outcomes (PROs) in adults with CHD.
Objective
The purpose of this study was to assess the impact of atrial arrhythmias on PROs in adults with CHD and explore geographic variations.
Methods
Associations between atrial arrhythmias and PROs were assessed in a cross-sectional study of adults with CHD from 15 countries spanning 5 continents. A propensity-based matching weight analysis was performed to compare quality of life, perceived health status, psychological distress, sense of coherence, and illness perception in patients with and those without atrial arrhythmias.
Results
A total of 4028 adults with CHD were enrolled, 707 (17.6%) of whom had atrial arrhythmias. After applying matching weights, patients with and those without atrial arrhythmias were comparable with regard to age (mean 40.1 vs 40.2 years), demographic variables (52.5% vs 52.2% women), and complexity of CHD (15.9% simple, 44.8% moderate, and 39.2% complex in both groups). Patients with atrial arrhythmias had significantly worse PRO scores with respect to quality of life, perceived health status, psychological distress (ie, depression), and illness perception. A summary score that combines all PRO measures was significantly lower in patients with atrial arrhythmias (-3.3%; P = .0006). Differences in PROs were consistent across geographic regions.
Conclusion
Atrial arrhythmias in adults with CHD are associated with an adverse impact on a broad range of PROs consistently across various geographic regions.

Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Apr 2021; 18:793-800
Casteigt B, Samuel M, Laplante L, Shohoudi A, ... Khairy P, of the APPROACH-IS Consortium and the International Society for Adult Congenital Heart Disease (ISACHD)
Heart Rhythm: 29 Apr 2021; 18:793-800 | PMID: 32961334
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Impact:
Abstract

Automated rhythm-based control of radiofrequency ablation close to the atrioventricular node: Preclinical, animal, and first-in-human testing.

Hooks DA, Dubois R, Meillet V, Nicot J, ... Haissaguerre M, Jais P
Background
The risk of heart block during radiofrequency ablation of atrioventricular (AV) nodal reentrant tachycardia and septal accessory pathways is minimized by rapidly ceasing ablation in response to markers of risk, such as atrioventricular dissociation, fast junctional rhythm, PR interval prolongation, or 2 consecutive atrial or ventricular depolarizations. Currently this is done manually.
Objectives
The objectives of this study were to build and test a control system able to monitor cardiac rhythm and automatically terminate ablation energy when required.
Methods
The device was built from off-shelf componentry. Preclinical testing involved real-time input of electrogram/electrocardiogram data from 209 ablation procedures (20 patients) over slow (n = 19) and fast (n = 1) AV nodal pathways. The device response speed was compared with the human response speed. The device\'s ability to prevent heart block was tested in 5 sheep. First-in-human testing was then performed in 12 patients undergoing AV nodal reentrant tachycardia ablation.
Results
Risk conditions necessitating shutoff of ablation (200 total; 111 preclinical and 89 first-in-human) were detected by the device with 100% sensitivity and 94% specificity, automatically terminating ablation while still allowing successful ablation in all patients. Device shutoff of ablation was always faster than human response (median difference 1.24 seconds). In each of 5 sheep, 40 consecutive attempts to cause heart block by ablating over the His bundle were unsuccessful because of automatic shutoff in response to rhythm change.
Conclusion
Automated shutoff of ablation close to the AV node in response to markers of the risk of heart block is feasible with high accuracy as well as faster response than human response. The system may improve the safety of ablation near the AV node by preventing heart block.

Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Apr 2021; 18:734-742
Hooks DA, Dubois R, Meillet V, Nicot J, ... Haissaguerre M, Jais P
Heart Rhythm: 29 Apr 2021; 18:734-742 | PMID: 33091601
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Impact:
Abstract

A circadian clock in the sinus node mediates day-night rhythms in Hcn4 and heart rate.

D\'Souza A, Wang Y, Anderson C, Bucchi A, ... DiFrancesco D, Boyett MR
Background
Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at night.
Objective
The lower heart rate during sleep is assumed to be neural in origin, but here we tested whether a day-night difference in intrinsic pacemaking is involved.
Methods
In vivo and in vitro electrocardiographic recordings, vagotomy, transgenics, quantitative polymerase chain reaction, Western blotting, immunohistochemistry, patch clamp, reporter bioluminescence recordings, and chromatin immunoprecipitation were used.
Results
The day-night difference in the average heart rate of mice was independent of fluctuations in average locomotor activity and persisted under pharmacological, surgical, and transgenic interruption of autonomic input to the heart. Spontaneous beating rate of isolated (ie, denervated) sinus node (SN) preparations exhibited a day-night rhythm concomitant with rhythmic messenger RNA expression of ion channels including hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4). In vitro studies demonstrated 24-hour rhythms in the human HCN4 promoter and the corresponding funny current. The day-night heart rate difference in mice was abolished by HCN block, both in vivo and in the isolated SN. Rhythmic expression of canonical circadian clock transcription factors, for example, Brain and muscle ARNT-Like 1 (BMAL1) and Cryptochrome (CRY) was identified in the SN and disruption of the local clock (by cardiomyocyte-specific knockout of Bmal1) abolished the day-night difference in Hcn4 and intrinsic heart rate. Chromatin immunoprecipitation revealed specific BMAL1 binding sites on Hcn4, linking the local clock with intrinsic rate control.
Conclusion
The circadian variation in heart rate involves SN local clock-dependent Hcn4 rhythmicity. Data reveal a novel regulator of heart rate and mechanistic insight into bradycardia during sleep.

Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Apr 2021; 18:801-810
D'Souza A, Wang Y, Anderson C, Bucchi A, ... DiFrancesco D, Boyett MR
Heart Rhythm: 29 Apr 2021; 18:801-810 | PMID: 33278629
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Abstract

Staphylococcus bacteremia without evidence of cardiac implantable electronic device infection.

Nakajima I, Narui R, Tokutake K, Norton CA, ... Crossley GH, Montgomery JA
Background
Staphylococcus bacteremia (SB) in the presence of a cardiac implantable electronic device (CIED) is frequently associated with CIED infection. In patients without clear CIED infection but SB, the role of empirical CIED removal is unclear.
Objective
The purpose of this study was to describe the natural history of SB in the setting of a CIED and the effect of CIED removal on mortality in patients with concurrent SB without evidence of CIED infection.
Methods
Three hundred sixty consecutive patients (mean age 61 ± 17 years; 255 (71%) men; 329 (92%) Staphylococcus aureus) with a CIED and concurrent SB were reviewed.
Results
At the initial presentation with SB, 178 patients had no evidence of CIED infection. Of these, 132 (74%) had another identified source of infection. Among the 178 patients without CIED infection, 18 (10%) had empirical CIED removal during the initial bacteremia. Among those who did not undergo CIED removal, SB subsequently relapsed in 19% and relapse rates were not different for those with or without another identifiable source at the initial presentation. Relapse was strongly associated with the duration of SB >1 day (odds ratio 9.99; 95% confidence interval 3.24-30.86). Despite the absence of CIED infection, 1-year mortality was 35% and empirical device removal during the initial presentation was associated with survival benefit (hazard ratio 0.28; 95% confidence interval 0.08-0.95).
Conclusion
For patients with SB without evidence of CIED infection, relapse is predicted by the duration of bacteremia. Empirical CIED removal appears to be associated with a survival benefit, although there are likely clinical situations in which this could be deferred.

Published by Elsevier Inc.

Heart Rhythm: 29 Apr 2021; 18:752-759
Nakajima I, Narui R, Tokutake K, Norton CA, ... Crossley GH, Montgomery JA
Heart Rhythm: 29 Apr 2021; 18:752-759 | PMID: 33321197
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Abstract

Long-term prognosis of women with Brugada syndrome and electrophysiological study.

Rodríguez-Mañero M, Jordá P, Hernandez J, Muñoz C, ... Brugada J, Arbelo E
Background
A male predominance in Brugada syndrome (BrS) has been widely reported, but scarce information on female patients with BrS is available.
Objective
The purpose of this study was to investigate the clinical characteristics and long-term prognosis of women with BrS.
Methods
A multicenter retrospective study of patients diagnosed with BrS and previous electrophysiological study (EPS) was performed.
Results
Among 770 patients, 177 (23%) were female. At presentation, 150 (84.7%) were asymptomatic. Females presented less frequently with a type 1 electrocardiographic pattern (30.5% vs 55.0%; P <.001), had a higher rate of family history of sudden cardiac death (49.7% vs 29.8%; P <.001), and had less sustained ventricular arrhythmias (VAs) on EPS (8.5% vs 15.1%; P = .009). Genetic testing was performed in 79 females (45% of the sample) and was positive in 34 (19%). An implantable cardioverter-defibrillator was inserted in 48 females (27.1%). During mean (± SD) follow-up of 122.17 ± 57.28 months, 5 females (2.8%) experienced a cardiovascular event compared to 42 males (7.1%; P = .04). On multivariable analysis, a positive genetic test (18.71; 95% confidence interval [CI] 1.82-192.53; P = .01) and atrial fibrillation (odds ratio 21.12; 95% CI 1.27-350.85; P = .03) were predictive of arrhythmic events, whereas VAs on EPS (neither with 1 or 2 extrastimuli nor 3 extrastimuli) were not.
Conclusion
Women with BrS represent a minor fraction among patients with BrS, and although their rate of events is low, they do not constitute a risk-free group. Neither clinical risk factors nor EPS predicts future arrhythmic events. Only atrial fibrillation and positive genetic test were identified as risk factors for future arrhythmic events.

Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Apr 2021; 18:664-671
Rodríguez-Mañero M, Jordá P, Hernandez J, Muñoz C, ... Brugada J, Arbelo E
Heart Rhythm: 29 Apr 2021; 18:664-671 | PMID: 33359877
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Abstract

The role of timing in treatment of atrial fibrillation: An AFFIRM substudy.

Yang E, Tang O, Metkus T, Berger RD, ... Calkins HG, Marine JE
Background
In contrast to historical trials, the Early Treatment of Atrial Fibrillation for Stroke Prevention Trial (EAST-AFNET 4) suggests the superiority of early rhythm control over rate control in patients with recent-onset atrial fibrillation (AF). The relative contribution of timing vs improvement in AF therapeutics over time is unclear.
Objective
This study aimed to isolate the assessment of early intervention for AF from temporal changes in AF treatments through a secondary analysis of subjects from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.
Methods
We compared rate and rhythm control treatments in AFFIRM subjects stratified by time from their diagnosis of AF. Time-to-event analysis was performed to compare all-cause mortality, cardiovascular hospitalizations, stroke, and number of hospitalization days.
Results
Of the 4060 AFFIRM subjects, 2526 subjects (62.2%) had their first episode of AF within 6 months of study enrollment. Participants with \"new\" AF had a decreased risk of all-cause mortality (P = .001) than did those with prior AF diagnoses. Individuals previously diagnosed with AF were similar in age and demographic characteristics, but had more medical comorbidities, including myocardial infarction (P = .006), diabetes mellitus (P = .002), smoking (P = .003), and hepatic or renal comorbidities (P = .008). There were no differences in mortality, cardiovascular hospitalizations, or stroke between rate and rhythm control strategies in either AF subgroup.
Conclusion
AFFIRM subjects diagnosed with AF within 6 months of study enrollment showed no difference in survival, cardiovascular hospitalization, or ischemic stroke between rate and rhythm control strategies. Superiority of rhythm control strategies reported by newer AF trials may be more attributable to the refinement of AF therapies and less related to the timing of intervention.

Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 29 Apr 2021; 18:674-681
Yang E, Tang O, Metkus T, Berger RD, ... Calkins HG, Marine JE
Heart Rhythm: 29 Apr 2021; 18:674-681 | PMID: 33383228
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