Journal: Heart Rhythm

Sorted by: date / impact
Abstract

The Terminal End of Retro-aortic root branch ------An unrecognized Origin for \" Proximal Left Anterior Fascicle\" Premature Ventricular Complexes with narrow QRS duration.

Zhang J, Li K, Ding Y, Tang C
Background
Premature ventricular complexes (PVCs) with narrow QRS duration, inferior frontal plane QRS axis and right bundle branch block(RBBB) pattern generally originate from the proximal segment of the left anterior fascicle(LAF).
Objective
This study aimed to investigate the exact origin of this category of PVCs.
Methods
22 patients with assumed proximal LAF-PVCs were enrolled in the present study. Detailed mapping of fascicular potentials (FPs) was performed during sinus rhythm (SR) and PVCs.
Results
During SR, a cluster of FPs could be found at the most superior portion of the left ventricle (LV). These FPs represented the terminal end of a discrete branch of the left fascicular system which we named the \"retro-aortic root branch\"(RARB). The shortest distance between the proximal LAF and the terminal end of RARB was 13.5±4.2mm. The earliest activation site of PVCs in all patients were confirmed at the terminal end of RARB, where the FP-V interval was 35.1±4.3 ms during PVCs. The shortest distance from the RCC to the EAS was 5.3±3.5mm. PVCs could be eliminated by ablation from the RCC in 45.5%(10/22) cases, in the remaining cases, ablation at the EAS in the LV endocardium successfully abolished PVCs.
Conclusions
The terminal end of the retro-aortic root branch was the actual origin site for PVCs with inferior frontal plane axis, RBBB pattern and narrow QRS duration. Ablation in the right coronary cusp or at the earliest activation site in the LV could both eliminate PVCs safely with high efficacy.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 11 May 2022; epub ahead of print
Zhang J, Li K, Ding Y, Tang C
Heart Rhythm: 11 May 2022; epub ahead of print | PMID: 35568133
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Aldehyde dehydrogenase 2 and arrhythmogenesis.

Jin J, Chen J, Wang Y
Cardiac arrhythmia is a common cardiovascular disease that leads to considerable economic burdens and significant global public health challenges. Despite the remarkable progress made in recent decades, antiarrhythmic therapy remains suboptimal. Aldehyde dehydrogenase 2 (ALDH2), a critical detoxifying enzyme, catalyzes toxic aldehydes and protects individuals from damages caused by oxidative stress. Accumulating evidence has demonstrated that ALDH2 activation has potential antiarrhythmic benefits. The correlation between ALDH2 deficiency and arrhythmogenesis has been widely recognized. In this review, we summarize recent researches on the potential roles of ALDH2 activation and antiarrhythmic protection, as well as the role played by the ALDH2*2 polymorphism (rs671) in promoting arrhythmic risk. Additionally, we discuss important new findings illustrating the use of ALDH2 activators, which may prove to be promising antiarrhythmic therapy agents.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 11 May 2022; epub ahead of print
Jin J, Chen J, Wang Y
Heart Rhythm: 11 May 2022; epub ahead of print | PMID: 35568135
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

The Secretome of Atrial Epicardial Adipose Tissue Facilitates Reentrant Arrhythmias by Myocardial Remodeling.

Ernault AC, Verkerk AO, Bayer JD, Aras K, ... de Groot JR, Coronel R
Background
Epicardial Adipose Tissue (EAT) accumulation is associated with cardiac arrhythmias. The effect of EAT secretome (EATs) on cardiac electrophysiology remains largely unknown.
Objective
This study investigated the arrhythmogenicity of EATs and its underlying molecular and electrophysiological mechanisms.
Methods
We collected atrial EAT and subcutaneous adipose tissue (SAT) from 30 patients with atrial fibrillation (AF), and EAT from 3 donors without AF. The secretome was collected after a 24-hour incubation of the adipose tissue explants. We cultured neonatal rat ventricular myocytes (NRVMs) with EATs, SAT secretome (SATs) and cardiomyocytes conditioned medium (CCM) for 72H. We implemented the electrophysiological changes observed after EATs incubation into a model of human left atrium and tested arrhythmia inducibility.
Results
Incubation of NRVMs with EATs decreased expression of the potassium channel subunit Kcnj2 by 26% and correspondingly reduced the inward rectifier K+ current (IK1) by 35% in comparison to incubation with CCM, resulting in a depolarized resting membrane of cardiomyocytes. EATs decreased expression of connexin43 (29% mRNA, 46% protein) in comparison to CCM. Cells incubated with SATs showed no significant differences in Kcnj2 nor Gja1 expression in comparison to CCM, and their resting potential was not depolarized. Cardiomyocytes incubated with EATs showed reduced conduction velocity and increased conduction heterogeneity compared to SATs and CCM. Computer modeling of human left atrium revealed that the electrophysiological changes induced by EATs promote sustained reentrant arrhythmias if EAT partially covers the myocardium.
Conclusion
EAT slows conduction, depolarizes the resting potential, alters electrical cell-cell coupling and facilitates reentrant arrhythmias.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 11 May 2022; epub ahead of print
Ernault AC, Verkerk AO, Bayer JD, Aras K, ... de Groot JR, Coronel R
Heart Rhythm: 11 May 2022; epub ahead of print | PMID: 35568136
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Cardiac Crises: Cardiac Arrhythmias and Cardiomyopathy during TANGO2-deficiency related Metabolic Crises.

Miyake CY, Lay EJ, Beach CM, Ceresnak SR, ... Lalani SR, Zhang L
Background
TANGO2 deficiency disorder (TDD) is an autosomal recessive disease associated with metabolic crisis, lethal cardiac arrhythmias, and cardiomyopathy1-7. Data regarding treatment, management, and outcomes of cardiac manifestations of TDD are lacking.
Objective
Describe TDD-related cardiac crises.
Methods
Retrospective multi-center chart review of TDD patients admitted with cardiac crises defined as development of ventricular tachycardia (VT), cardiomyopathy, or cardiac arrest during metabolic crises.
Results
27 children were admitted for 43 cardiac crises (median age 6.4 years, IQR 2.4-9.8y) at 14 centers. During crisis, QTc prolongation occurred in all (median 547msec, IQR 504-600msec) and a type I Brugada pattern in 8 (26%). Arrhythmias included VT in 21 (78%), SVT in 3 (11%) and heart block in 1 (4%). Nineteen (70%) developed cardiomyopathy and 20 (74%) suffered a cardiac arrest. There were 10 deaths (37%), 6 related to arrhythmias. In 5 recalcitrant VT occurred despite use of antiarrhythmics. In 6 arrhythmias were controlled after extracorporeal membrane oxygenation (ECMO) support, 5 of whom survived. Among 10 who survived VT without ECMO, successful treatment included intravenous magnesium, isoproterenol, and atrial pacing in multiple cases and verapamil in 1 patient. Initiation of feeds appeared to decrease VT events.
Conclusions
TDD-related cardiac crises are associated with a high-risk of arrhythmias, cardiomyopathy, cardiac arrest, and death. Although further studies are needed, early recognition and appropriate treatment is critical. Acutely, intravenous magnesium, isoproterenol, atrial pacing, and ECMO as a last resort appear to be the best current treatment options and early initiation of feeds may prevent VT events.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 11 May 2022; epub ahead of print
Miyake CY, Lay EJ, Beach CM, Ceresnak SR, ... Lalani SR, Zhang L
Heart Rhythm: 11 May 2022; epub ahead of print | PMID: 35568137
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Analysis of site-specific late potentials using a novel Holter signal-averaged electrocardiography in patients with Brugada syndrome.

Takahashi H, Takagi M, Yoshio T, Yoh M, Shiojima I
Background
The utility of late potentials on signal-averaged electrocardiography (SAECG) for risk stratification in patients with Brugada syndrome (BrS) remains controversial. Late potentials on conventional SAECG with Frank leads may be insufficiently sensitive to detect the site-specific late potentials in right precordial leads.
Objective
We evaluated the utility of site-specific late potentials using a novel unipolar Holter-SAECG system for risk stratification in patients with BrS.
Methods
Consecutive symptomatic (n=20) and asymptomatic (n=21) patients with BrS who underwent investigation using conventional SAECG and a novel unipolar Holter-SAECG system were enrolled. We evaluated clinical characteristics and outcomes and compared late potentials on the both SAECGs between both groups and patients with and without cardiac events (CEs; sudden cardiac death or sustained ventricular tachyarrhythmias) during the follow-up period.
Results
During a mean follow-up of 76 months, ten patients (24%) had CEs. There were no significant differences in late potentials on conventional SAECG between symptomatic and asymptomatic patients. On the Holter-SAECG system, the value of RMS40 in lead V2 in the third intercostal space (3L-V2) at the nighttime was significantly lower in the symptomatic group than in the asymptomatic group (5.5 ± 0.8 and 8.2 ± 0.8 μV, respectively; p=0.027). Univariate analysis of predictive values for cardiac event showed that hazard ratios of daytime and nighttime RMS40 in lead 3L-V2 of <7.7 μV and <6.1 μV were 7.58 and 6.14, respectively.
Conclusions
Site-specific late potentials in lead 3L-V2 measured using the novel Holter-SAECG system may be a useful marker for high-risk patients with BrS.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 10 May 2022; epub ahead of print
Takahashi H, Takagi M, Yoshio T, Yoh M, Shiojima I
Heart Rhythm: 10 May 2022; epub ahead of print | PMID: 35562054
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Left Bundle Branch Area Pacing in Patients with Atrioventricular Conduction Disease: A Prospective Multicenter Study.

Raymond-Paquin A, Verma A, Kolominsky J, Sanchez-Somonte P, ... Koneru JN, Ellenbogen KA
Background
The reported success rate of His bundle pacing (HBP) in patients with infranodal atrioventricular (AV) conduction disease is only 52-76%. The success rate of left bundle branch area pacing (LBBAP) in this cohort is not well studied.
Objective
To evaluate the feasibility, safety, and electrophysiological characteristics of LBBAP in patients with AV conduction disease.
Methods
Patients with AV conduction disease referred for pacemaker implantation at two centers between 02/2019 and 6/2021 were considered for LBBAP. Baseline demographic characteristics, procedural success rates, electrophysiological parameters and complications were assessed.
Results
LBBAP was successful in 340/364 (93%) patients. Mean age was 72±13 years and mean follow-up was 331±244 days. Pacing indications were Mobitz I in 27 patients (7%), Mobitz II or 2:1 AV block or high-grade AV block in 94 patients (26%), complete heart block in 199 patients (55%) and sick sinus syndrome with isolated bundle branch block in 44 patients (12%). LBBB and RBBB were present in 57 patients (16%) and 140 patients (38%) respectively. Procedural success rates did not differ between indications (92.6%, 93.6%, 92.9% and 95% respectively) or between patients with narrow (<120ms) versus wide QRS (≥120ms). Mean LBBAP threshold was 0.77±0.34V at 0.4ms at implant and remained stable during follow-up. There were 4 (1.2%) acute LBBAP lead dislodgements.
Conclusions
LBBAP is safe and feasible with high success rates for patients with AV conduction disease. Contrary to HBP, LBBAP success rates remain high over the entire spectrum of AV conduction disease and lead parameters remain stable during follow-up.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 10 May 2022; epub ahead of print
Raymond-Paquin A, Verma A, Kolominsky J, Sanchez-Somonte P, ... Koneru JN, Ellenbogen KA
Heart Rhythm: 10 May 2022; epub ahead of print | PMID: 35562056
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Contemporary Maternal and Fetal Outcomes in Treatment of LQTS during Pregnancy: Is Nadolol Bad for the Fetus?

Hammond BH, El Assaad I, Herber JM, Saarel EV, Cantillon D, Aziz PF
Background
Beta blocker therapy, specifically nadolol, is the recommended treatment for long QT syndrome (LQTS). Previous studies assessing maternal and fetal outcomes were published prior to nadolol era.
Objectives
The purpose of this study was to examine contemporary maternal and fetal outcomes in treatment of LQTS during pregnancy.
Methods
We queried the Inherited Arrhythmia Database at Cleveland Clinic and identified all pregnant LQTS patients from January 2001 to January 2020. Collected data included use and timing of beta-blockers, maternal arrhythmia events, fetal growth restriction, neonatal hypoglycemia and bradycardia.
Results
Among 68 live-birth pregnancies in 31 women with LQTS (mean age 29 ± 5.9 years, mean QTc 468 ± 39 ms), there were 5 arrhythmia events in 4 mothers. All arrhythmia events occurred in the post-partum period and there were no arrhythmia events in patients taking beta blockers. In diagnosed LQTS patients treated with beta blockers (n=27, 41%), nadolol was the most commonly prescribed agent throughout pregnancy and postpartum period (n=16, 60%). The rate of intrauterine growth restriction (IUGR) was not significantly different in fetuses exposed to beta blockers vs. unexposed (p=0.08). In the postnatal period, hypoglycemia was not seen and one patient in the exposure group had bradycardia.
Conclusions
Arrhythmia events were only seen in the post-partum period in those not treated with beta blockers. Events occurred as late as 9 months postpartum. Beta blocker therapy, specifically nadolol, was not associated with higher incidence of IUGR. Moreover, neonatal bradycardia was rare and hypoglycemia was not observed.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 04 May 2022; epub ahead of print
Hammond BH, El Assaad I, Herber JM, Saarel EV, Cantillon D, Aziz PF
Heart Rhythm: 04 May 2022; epub ahead of print | PMID: 35525421
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Skin Sympathetic Nerve Activity and Ventricular Arrhythmias in Acute Coronary Syndrome.

Huang TC, Lin SJ, Chen CJ, Jhuo SJ, ... Lin SF, Tsai WC
Background
Acute coronary syndrome (ACS) is major cause of ventricular arrhythmias (VA) and sudden death. neuECG is a non-invasive method to simultaneously measure skin sympathetic nerve activity (SKNA) and electrocardiogram (ECG).
Objective
To test the hypotheses that (1) ACS increases the average SKNA (aSKNA), (2) the magnitude of aSKNA elevation is associated with VA during ACS and (3) there is a gender difference of aSKNA in patients without and with ACS.
Methods
We prospectively studied 128 ACS and 165 control participants. The neuECG was recorded with electrocardiogram (ECG) Lead I configuration at baseline, during mental math stress and during recovery (5-min each). All recordings were done in the morning.
Results
In control group, women have higher aSKNA (μV) than men at baseline (0.82±0.25 vs 0.73±0.20, p=0.009) but not during mental stress (1.21±0.36 vs 1.16±0.36, p=0.394), suggesting women had lower sympathetic reserve. In comparison, ACS is associated with equally elevated aSKNA (μV) in women vs men at baseline (1.14±0.33 vs 1.04±0.35, p=0.531), during mental stress (1.46±0.32 vs 1.33 ±0.37, p=0.113) and during recovery (1.30±0.33 1.11±0.30, p=0.075). After adjusting for age and gender, the adjusted odds ratio for VA including ventricular tachycardia and fibrillation is 1.23 (95% confidence interval 1.05-1.44) for each 0.1 μV elevation of aSKNA. The aSKNA is positively correlated with plasma norepinephrine level.
Conclusions
ACS is associated with elevated aSKNA and the magnitude of aSKNA elevation is associated with occurrences of VA. Women have higher aSKNA and lower SKNA reserve than men in control but not in ACS patients.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 04 May 2022; epub ahead of print
Huang TC, Lin SJ, Chen CJ, Jhuo SJ, ... Lin SF, Tsai WC
Heart Rhythm: 04 May 2022; epub ahead of print | PMID: 35525422
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Pacing Burden and Clinical Outcomes Following Transcatheter Aortic Valve Replacement - A Real-World Registry Report.

Natanzon SS, Fardman A, Koren-Morag N, Fefer P, ... Nof E, Beinart R
Introduction
Conflicting data exists regarding the prognostic significance of permanent pacemaker (PPM) implantation following TAVR.
Objective
Evaluate whether PPM implantation post TAVR is associated with adverse outcomes.
Methods
A retrospective analysis of a cohort comprised of patients enrolled to a prospective registry between 2008-2019. Participants were allocated into three groups: patients without prior pacemaker (n=930, 75%), patients with previous pacemaker implantation (n=118, 10%) and those with pacemaker implantation following TAVR (n=191, 15%). Primary outcome included death and heart failure hospitalizations at 1 year. Secondary outcomes included death and heart failure hospitalizations stratified by pacing burden.
Results
A total of 1239 patients underwent TAVR with median follow up of 2.3 years (IQR 1-4). Patients with previous and new pacemaker implantation were older [84 (80-88), 84 (80-88), 82 (78-86), p-0.009)], and had lower baseline LVEF (50%±15%, 55%±12%, 56%±12%, p<0.001). Patients who underwent new pacemaker implantations had higher combined outcome of death and heart failure hospitalizations (21%,12% ,14%, p-0.01). New pacemaker implantation was associated with almost twice the risk of 1-year mortality (HR-1.85, 95% C.I 1.13-3.02, p-0.014). Pacing burden, however, was not associated with the primary outcome. Furthermore, no significant difference was observed at long term follow up [cumulative probability to develop primary endpoint at 3 years was 57%±2% (without PPM), 57%±6% (prior PPM), 54%±4% (new PPM), p-0.52].
Conclusion
Pacemaker implantation following TAVR is associated with higher 1-year adverse outcome, but this attenuates over time, suggesting that competing factors may play a role. Interestingly, pacing burden is not associated with adverse clinical course.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 04 May 2022; epub ahead of print
Natanzon SS, Fardman A, Koren-Morag N, Fefer P, ... Nof E, Beinart R
Heart Rhythm: 04 May 2022; epub ahead of print | PMID: 35525423
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Effects of beta-blockers on ventricular repolarization documented by 24-h electrocardiography in long-QT syndrome type 2.

Koponen M, Marjamaa A, Väänänen H, Tuiskula AM, ... Swan H, Viitasalo M
Background
Long QT syndrome (LQTS) is an inherited arrhythmia disorder characterized by ventricular repolarization abnormalities and a risk of sudden cardiac death. The electrophysiological components generating the high risk of arrhythmias in LQTS are prolonged repolarization, increased dispersion of repolarization, and early afterdepolarizations, which are clinically estimated as QT interval, T-wave peak to end (TPE) interval, and T2/T1-wave amplitude ratio, respectively. In experimental LQTS type 2 (LQT2) models, beta-blockers decrease dispersion of repolarization and prevent early afterdepolarizations. In clinical studies among LQT2 patients beta-blockers are more effective against exercise-induced than arousal-induced cardiac events.
Objectives and methods
The aim of the study was to investigate the effects of beta-blocker therapy on QT and TPE intervals, and maximal T2/T1-wave amplitude ratios recorded by 24-h electrocardiograms (ECG) among 25 LQT2 patients.
Results
Beta-blocker therapy decreased the maximal T2/T1-wave amplitude ratio from 2.9±1.1 to 1.8±0.7 (p<0.001), but did not change pause-induced T2/T1-wave amplitude ratio. Under medication abrupt maximal TPE intervals were shorter at heart rates of 75 beats/min or over, and maximal QT intervals were shorter at a heart rate of 100 beats/min.
Conclusions
Beta-blockers stabilize ventricular repolarization in LQT2 by reducing electrocardiographic early afterdepolarizations, and by reducing abrupt prolongation of electrocardiographic dispersion of repolarization and ventricular repolarization duration at elevated heart rates. The effect of beta-blockers on pause-induced electrocardiographic early afterdepolarizations is weak. The findings provide electrocardiographic explanation for the protective effects of beta-blockers against exercise-induced cardiac events in LQT2.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 04 May 2022; epub ahead of print
Koponen M, Marjamaa A, Väänänen H, Tuiskula AM, ... Swan H, Viitasalo M
Heart Rhythm: 04 May 2022; epub ahead of print | PMID: 35525424
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Sex Hormones and Repolarization Dynamics during the Menstrual Cycle in Women with Congenital Long QT Syndrome.

Bjelic M, Zareba W, Peterson DR, Younis A, ... Ackerman MJ, Goldenberg I
Background
Women with congenital long QT syndrome (LQTS) experience increased cardiac events risk after the onset of adolescence, perhaps stemming from the known modulating effects of sex hormones on the cardiac potassium channels.
Objective
We hypothesized that the effect of sex hormones on cardiac ion channel function may modify ECG parameters associated with the propensity for ventricular tachyarrhythmias during the menstrual cycle in women with LQTS.
Methods
We prospectively enrolled 65 women with congenital LQTS (LQT1 [N=24], LQT2 [N=20]) and unaffected female relatives [N=21]. Subjects underwent three 7-day ECG recordings during their menstrual cycles. Simultaneous saliva testing of sex hormone levels was obtained on the first day of each 7-day ECG recording cycle.
Results
Mean age was 35±8 years, without a significant difference among the groups. In LQT2 women, linear mixed effects models showed significant inverse correlations of QTc with progesterone (p<0.001), and the progesterone to estradiol ratio (p<0.001). Inverse relationships of the RR interval with estradiol levels (p=0.003) and of the T-wave duration with testosterone levels (p=0.014) were also observed in women with LQT2. In contrast, no significant associations were observed between ECG parameters and sex hormone levels the women with LQT1 women or the unaffected relatives.
Conclusions
This is the first study to prospectively assess correlations between repolarization dynamics and sex hormone levels during the menstrual cycle in women with congenital LQTS. Our findings show genotype-specific unique QTc dynamics during the menstrual cycle that may affect the propensity for ventricular tachyarrhythmia in women with LQTS, particularly LQT2 women.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 04 May 2022; epub ahead of print
Bjelic M, Zareba W, Peterson DR, Younis A, ... Ackerman MJ, Goldenberg I
Heart Rhythm: 04 May 2022; epub ahead of print | PMID: 35525425
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Temporal and geographical trends in women operators of electrophysiology procedures in the United States.

Howell SJ, Simpson T, Atkinson T, Pellegrini CN, Nazer B
Background
Cardiac electrophysiology (EP) has few women physicians.
Objective
The purpose of this study was to determine temporal and geographical trends in the proportion of women EP operators in the United States.
Methods
We extracted data from the Medicare Provider Utilization and Payment Database from 2013 to 2019 using procedure codes for atrial fibrillation (AF) ablation, supraventricular tachycardia/atrial flutter (SVT/AFL) ablation, and cardiac device implantation. The Medicare Provider Utilization and Payment Database excludes operators who perform ≤10 procedures annually for a given individual procedure code. The proportion of women operators was compared across the 7-year period.
Results
On average annually between 2013 and 2019, 5% (n = 187) of the 3524 EP operators were women. Procedure-specific analyses demonstrated a similarly low proportion of women EP operators across each procedure type. Despite a 137% increase in the total number of AF ablationists over the 7-year period, the proportion of women remained unchanged (P = .3966). The number of SVT/AFL ablationists and device operators remained constant over time as did the proportion of women operators (P = .9709 and .3583, respectively). In 2019, 10 states (20%) had no women EP operators who performed >10 of any given EP procedure annually, 20 states (39%) had no women who performed >10 of either AF or SVT/AFL ablation procedures annually, and 10 states (20%) had no women device operators who performed >10 of any given type of device implantation annually.
Conclusion
Women EP operators remain underrepresented, and the proportion of women is stagnant even in areas of major clinical growth such as AF ablation. One-fifth of states had no women operators who performed >10 of any given EP procedure annually.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 01 May 2022; 19:807-811
Howell SJ, Simpson T, Atkinson T, Pellegrini CN, Nazer B
Heart Rhythm: 01 May 2022; 19:807-811 | PMID: 35501106
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Current of Injury is an Indicator of Lead Depth and Performance during Left Bundle Branch Pacing Lead Implantation.

Shali S, Wu W, Bai J, Wang W, ... Chen X, Ge J
Background
Monitoring of lead depth is crucial to achieve left bundle branch pacing (LBBP) with a low capture threshold and avoid septal perforation, but lacks informative approach.
Objective
We aimed to prospectively assess the predictive value of current of injury on the occurrence of inadequate LBB capture threshold and acute septal perforation.
Methods
Consecutive patients who received LBBP were enrolled. ST-segment elevation ≥ 25% of intrinsic R wave amplitude on the unipolar intracardiac electrogram was defined as a sign of distinct current of injury. A LBB capture threshold < 1.5 V / 0.5 ms was considered acceptable.
Results
LBBP was attempted 513 times in 212 patients. LBB capture threshold was more likely to improve to an acceptable level after 10min in cases with initial (33/47 vs. 0/8, with vs. without) and residual (29/33 vs. 4/14, with vs. without) current of injury on the tip electrode (p < 0.0001). Lead perforation during the procedure has occurred in 11 cases who had no current of injury on the tip electrode. The ratio of current of injury on the tip electrode to that on the ring electrode was correlated to the lead depth determined by sheath angiography (Spearman\'s Correlation Coefficient = -0.624, p < 0.0001), and microperforation is highly possible when the ratio is decreased to <1 (sensitivity: 100% and specificity: 96.6%).
Conclusions
Current of injury is a useful tool in forecasting LBBP lead depth and septal perforation, and it could facilitate the decision-making process when the initial LBB capture threshold is undesirable.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 29 Apr 2022; epub ahead of print
Shali S, Wu W, Bai J, Wang W, ... Chen X, Ge J
Heart Rhythm: 29 Apr 2022; epub ahead of print | PMID: 35500789
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Factors Associated with Remote Monitoring Adherence for Cardiovascular Implantable Electronic Devices.

Muniyappa AN, Raitt MH, Judson GL, Shen H, ... Whooley MA, Dhruva SS
Background
Professional societies strongly recommend remote monitoring (RM) of all cardiac implantable electronic devices (CIEDs), and higher RM adherence is associated with improved patient outcomes. However, adherence with RM is sub-optimal.
Objective
To better understand factors associated with remote monitoring adherence.
Methods
We linked RM data from the Veterans Affairs National Cardiac Device Surveillance Program to clinical data for patients monitored between October 25, 2018 and October 24, 2020. RM adherence was defined as the percentage of days covered by a RM transmission during the study period. Patients were categorized as complete (100% of days covered by a RM transmission), intermediate (above median among patients with <100% adherence), and low (below median among patients with <100% adherence) adherence. We used multivariable logistic regression to examine patient, device, and facility characteristics associated with adherence.
Results
Among 52,574 patients, average RM adherence was 71.9%. Only 30.9% of patients had complete RM adherence. Black or African American patients had lower odds of complete RM adherence compared with white patients (odds ratio [OR] 0.88, 95% confidence interval [CI]: 0.82-0.94), and Hispanic or Latino patients had lower odds of complete RM adherence (OR 0.79, 95% CI: 0.70-0.89) compared with non-Hispanic or Latino patients. Dementia, depression, and post-traumatic stress disorder were associated with lower odds of RM adherence.
Conclusion
There are significant disparities in RM adherence by race, ethnicity, and neuropsychiatric comorbidities. These findings can inform strategies to improve health equity and ensure all patients with CIEDs receive the evidence-based clinical benefits of RM.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 29 Apr 2022; epub ahead of print
Muniyappa AN, Raitt MH, Judson GL, Shen H, ... Whooley MA, Dhruva SS
Heart Rhythm: 29 Apr 2022; epub ahead of print | PMID: 35500792
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Rescue Left Bundle Branch Area Pacing in Coronary Venous Lead Failure or Non-response to Biventricular Pacing: Results From International LBBAP Collaborative Study Group.

Vijayaraman P, Herweg B, Verma A, Sharma PS, ... Jastrzebski M, Ellenbogen KA
Background
Cardiac resynchronization therapy (CRT) using biventricular pacing (BVP) is effective in patients with heart failure, left bundle branch block (LBBB) and reduced left ventricular function. Left bundle branch area pacing (LBBAP) has been reported as an alternative option for CRT.
Objective
The aim of this study was to assess the feasibility and outcomes of LBBAP in patients who failed conventional BVP due to coronary venous lead complications or were non-responders to BVP.
Methods
At 16 international centers, LBBAP was attempted in patients with conventional CRT indication who failed BVP due to either, coronary venous (CV) lead complications, or lack of therapeutic response to BVP. We are reporting heart failure hospitalizations (HFH) and death, echocardiographic outcomes, procedural data, pacing parameters, and lead complications including CV lead failure.
Results
LBBAP was successfully performed in 200 patients (CV lead failures-156; non-responders-44): age 68±11years, female-35%, LBBB-55%, RVP-23%, ischemic cardiomyopathy-28%, nonischemic cardiomyopathy-63%, LVEF ≤35% in 80%. Procedure and fluoroscopy duration were 119.5±59.6 and 25.7±18.5 min. LBBAP threshold and R-wave amplitudes were 0.68±0.35V@0.45ms and 10.4±5mV at implant and remained stable during mean follow-up of 12±10.1 months. LBBAP resulted in significant QRS narrowing from 170±28ms to 139±25ms (p<0.001) with V6 R-wave peak times of 85±17ms. LVEF improved from 29±10% at baseline to 40±12% (p<0.001) during follow-up. The risk for death or HFH was lower in CV lead failure compared to non-responders (HR-0.357;95%CI 0.168-0.756,p=0.007)
Conclusion:
LBBAP is a viable alternative for CRT in patients who failed conventional BVP due to CV lead failure or were non-responders.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 27 Apr 2022; epub ahead of print
Vijayaraman P, Herweg B, Verma A, Sharma PS, ... Jastrzebski M, Ellenbogen KA
Heart Rhythm: 27 Apr 2022; epub ahead of print | PMID: 35504539
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

2022 HRS expert consensus statement on evaluation and management of arrhythmic risk in neuromuscular disorders.

Groh WJ, Bhakta D, Tomaselli GF, Aleong RG, ... Wheeler MT, Zeppenfeld K
This international multidisciplinary document is intended to guide electrophysiologists, cardiologists, other clinicians, and health care professionals in caring for patients with arrhythmic complications of neuromuscular disorders (NMDs). The document presents an overview of arrhythmias in NMDs followed by detailed sections on specific disorders: Duchenne muscular dystrophy, Becker muscular dystrophy, and limb-girdle muscular dystrophy type 2; myotonic dystrophy type 1 and type 2; Emery-Dreifuss muscular dystrophy and limb-girdle muscular dystrophy type 1B; facioscapulohumeral muscular dystrophy; and mitochondrial myopathies, including Friedreich ataxia and Kearns-Sayre syndrome, with an emphasis on managing arrhythmic cardiac manifestations. End-of-life management of arrhythmias in patients with NMDs is also covered. The document sections were drafted by the writing committee members according to their area of expertise. The recommendations represent the consensus opinion of the expert writing group, graded by class of recommendation and level of evidence utilizing defined criteria. The recommendations were made available for public comment; the document underwent review by Heart Rhythm Society Scientific and Clinical Documents Committee and external review and endorsement by the partner and collaborating societies. Changes were incorporated based on these reviews. By using a breadth of accumulated available evidence, the document is designed to provide practical and actionable clinical information and recommendations for the diagnosis and management of arrhythmias and thus improve the care of patients with NMDs.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 26 Apr 2022; epub ahead of print
Groh WJ, Bhakta D, Tomaselli GF, Aleong RG, ... Wheeler MT, Zeppenfeld K
Heart Rhythm: 26 Apr 2022; epub ahead of print | PMID: 35500790
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Clinical Outcomes Of Conduction System Pacing Compared To Biventricular Pacing In Patients Requiring Cardiac Resynchronization Therapy.

Vijayaraman P, Zalavadia D, Haseeb A, Dye C, ... Subzposh FA, Sharma PS
Background
Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is well-established therapy in patients with reduced left ventricular ejection fraction (LVEF) and bundle branch block or indication for pacing. Conduction system pacing (CSP) utilizing His bundle pacing or left bundle branch area pacing has been shown to be a safe and a more physiologic alternative to BVP.
Objective
The aim of this study was to compare the clinical outcomes between CSP and BVP among patients undergoing CRT.
Methods
This observational study included consecutive patients with LVEF≤35% and Class I or II indications for CRT who underwent successful BVP or CSP at two major healthcare systems. The primary outcome was the composite endpoint of time to death or heart failure hospitalization (HFH). Secondary outcomes included subgroup analysis in LBBB as well as individual endpoints of death and HFH.
Results
A total of 477 patients (32% female) met inclusion criteria: BVP 219; CSP 258 (HBP 87, LBBAP 171). Mean age was 72±12 years and mean LVEF 26±6%. Co-morbidities included HTN 70%, DM 45%, CAD 52%. Paced QRS duration in CSP was significantly narrower than BVP (133±21 vs 153±24ms, p<0.001). LVEF improved in both groups during a mean f/u of 27±12 months and was greater after CSP compared to BVP (39.7±13 vs 33.1±12%, p<0.001). Primary outcome of death or HFH was significantly lower in the CSP vs BVP (28.3% vs 38.4%; HR 1.52; CI 1.082-2.087;p=0.013).
Conclusions
CSP improved clinical outcomes compared to BVP in this large cohort of patients with indications for CRT.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 26 Apr 2022; epub ahead of print
Vijayaraman P, Zalavadia D, Haseeb A, Dye C, ... Subzposh FA, Sharma PS
Heart Rhythm: 26 Apr 2022; epub ahead of print | PMID: 35500791
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

The Risk of Sudden Cardiac Death Associated with QRS, QTc and JTc intervals in the General Population Revision #4.

Tikkanen JT, Kentta T, Porthan K, Anttonen O, ... Huikuri HV, Junttila MJ
Background
QRS duration and QTc interval have been associated with sudden cardiac death (SCD), but no data is available on the significance of repolarization component (JTc interval) of QTc as an independent risk marker in the general population.
Objective
In this study, we sought to quantify the risk of SCD associated with QRS, QTc and JTc.
Methods
This study was conducted using data from 3 population cohorts from different eras, comprising a total of 20,058 individuals. The follow-up was limited to 10 years and age at baseline to 30-61 years. QRS duration and QT interval (Bazett\'s) were measured from standard 12-lead electrocardiograms at baseline. JTc interval was defined as QTc - QRS duration. Cox proportional hazard models that controlled for confounding clinical factors identified at baseline were used to estimate the relative risk of SCD.
Results
During a mean period of 9.7 years, 207 SCDs occurred (1.1 per 1000 person-years). QRS duration was associated with a significantly increased risk of SCD in each cohort (pooled hazard ratio 1.030 per 1 ms increase (95% confidence interval 1.017-1.043). The QTc interval had borderline to significant associations with SCD and varied among cohorts (pooled HR 1.007, 95%CI 1.001-1.012). JTc interval as a continuous variable was not associated with SCD (pooled HR 1.001, 95%CI 0.996-1.007).
Conclusions
Prolonged QRS durations and QTc intervals are associated with an increased risk of sudden cardiac death. However, when QTc is deconstructed into QRS and JTc intervals, the repolarization component (JTc) appears to have no independent prognostic value.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 23 Apr 2022; epub ahead of print
Tikkanen JT, Kentta T, Porthan K, Anttonen O, ... Huikuri HV, Junttila MJ
Heart Rhythm: 23 Apr 2022; epub ahead of print | PMID: 35472593
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

CLINICAL PROFILE AND LONG-TERM FOLLOW-UP OF A COHORT OF PATIENTS WITH DESMOPLAKIN CARDIOMYOPATHY.

Bariani R, Cason M, Rigato I, Cipriani A, ... Pilichou K, Bauce B
Background
Desmoplakin (DSP) genetic variants have been reported in Arrhythmogenic Cardiomyopathy (ACM) with particular regard to predominant left ventricular involvement.
Objective
To improve our understanding of clinical phenotype and outcome of DSP variant carriers.
Methods
Clinical picture and outcome of 73 patients (36% probands) harboring a pathogenic/likely pathogenic (P/LP) DSP variant were evaluated.
Results
The phenotype during follow-up (mean 11 years, range 1-39) changed in 25 patients (35%), Arrhythmogenic Left Ventricular Cardiomyopathy (ALVC) forms being the most frequent (n=26, 36%), followed by biventricular forms (BIV n=20, 27%) and Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC, n=16, 22%). Major ventricular arrhythmias were detected in 21 patients (29%), and they were more common in ARVC (56%) and BIV (40%) than in ALVC (15%) forms. In ALVC patients, major ventricular arrhythmias occurred in the setting of a normal/mildly reduced systolic function. Heart failure (HF) occurred in 8 patients, none affected with ALVC. Females showed more commonly a LV involvement, while ARVC forms were more frequently detected in males (61% vs 38%, p=0.147). Males showed a higher incidence of major ventricular arrhythmias (52% vs 24%, p=0.036), HF (31% vs 3%, p=0.004) and cardiac death (31% vs 0%, p<0.001).
Conclusions
Clinical phenotype in P/LP DSP variant carriers is wide. Although most patients show a LV involvement, 22% has RV abnormalities in keeping with a \"classical\" ACM form. In ALVC, HF and major ventricular arrhythmias seem less common compared to RV and BIV variants. Females show more frequently a LV involvement and a better outcome.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 22 Apr 2022; epub ahead of print
Bariani R, Cason M, Rigato I, Cipriani A, ... Pilichou K, Bauce B
Heart Rhythm: 22 Apr 2022; epub ahead of print | PMID: 35470109
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Ultrasound-guided extra-cardiac vagal stimulation - new approach for visualization of vagus nerve during cardioneuroablation.

Piotrowski R, Zuk A, Baran J, Sikorska A, Krynski T, Kulakowski P
Background
The fluoroscopy-guided ECVS from the internal right and left jugular veins (RIJV/LIJV) is routinely used to document vagal response (sinus arrest (SA) and/or atrio-ventricular block (AVB)) during cardioneuroablation. The ultrasound-guided ECVS allows direct visualization and selective stimulation of the vagus nerve (VN).
Objective
To assess feasibility of ultrasound-guided extra-cardiac vagal stimulation (ECVS) and to compare it with fluoroscopy-guided ECVS.
Methods
The study group consisted of 48 patients (25 males, mean age 38±15 years) in whom fluoroscopy-guided ECVS and ultrasound-guided ECVS were performed. For fluoroscopy-guided ECVS, pacing electrode was introduced into the RIJV and to the LIJV up to the level of the jugular foramen under fluoroscopic guidance. For ultrasound-guided ECVS, VN and electrode were visualized using USG. Partial vagal response was defined as induction of SA or AVB whereas full vagal response-induction of both.
Results
ECVS was performed in all patients from RIJV and in 45 from LIJV. Visualization of the VN using ultrasound was possible in 44 (92%) patients. During ECVS from RIJV, partial vagal response was obtained in 39 (81%) using fluoroscopy-guided ECVS vs 45 (94%) using ultrasound-guided-ECVS (NS) whereas full vagal response-in 27 (56%) patients using fluoroscopy-guided ECVS vs 40 (83%) using ultrasound-guided ECVS (p=0.0071). For ECVS from LIJV, partial vagal response was achieved in 40 (89%) vs 44 (98%) patients (NS) whereas full vagal response-in 30 (67%) vs 40 (89%) patients (p=0.021) (fluoroscopy-guided ECVS vs ultrasound-guided ECVS, respectively).
Conclusion
Ultrasound-guided-ECVS is feasible and full vagal response is achieved significantly more frequently than using fluoroscopy-guided ECVS.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 21 Apr 2022; epub ahead of print
Piotrowski R, Zuk A, Baran J, Sikorska A, Krynski T, Kulakowski P
Heart Rhythm: 21 Apr 2022; epub ahead of print | PMID: 35462051
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Postnatal Recurrence and Transesophageal Inducibility of Prenatally Treated Fetal Supraventricular Tachycardia.

Michel M, Renaud C, Chiu-Man C, Gross G, Jaeggi E
Background
Antiarrhythmic treatment of fetal supraventricular tachycardia (SVT) is used to prevent morbidity and mortality. The postnatal management of survivors is often arbitrary and varied.
Objectives
To examine the utility of a risk-based postnatal management strategy.
Methods
Sixty-six prenatally treated newborns with fetal long or short VA tachycardia were reviewed. Postnatal diagnoses included AV-reentrant (AVRT), atrial ectopic (AET), and permanent junctional reciprocating (PJRT) tachycardia. Unless the SVT persisted to birth, early neonatal observation without treatment was recommended. For newborns without spontaneous arrhythmia after ≥2 days of observation, inducibility was tested by transesophageal pacing study (TEPS). Postnatal therapy was advised for spontaneous or inducible SVT. Characteristics associated with these outcomes were analyzed.
Results
Twenty-eight (42%) cases experienced SVT at/early after birth, which was associated with fetal long VA tachycardia (odds ratio (OR) 6.8; 95% confidence interval (CI) 1.88-24.57; p=0.0029); delayed in-utero cardioversion with treatment (median 11 vs. 5.5 days; p<0.0001); prenatal treatment with multiple antiarrhythmics (OR 4.42; CI 1.56-12.55; p=0.0059); and postnatal AET/PJRT (OR 18.0; CI 2.11-153.9; p=0.0013). Of 38 neonates undergoing TEPS, 19 had inducible tachyarrhythmias. Recurrence of SVT during infancy or childhood was documented in 4/6 (66%) cases with SVT at birth, 8/22 (36%) with early neonatal SVT, 4/19 (21%) with inducible SVT and 0/19 (0%) untreated cases without inducible SVT (p=0.0032).
Conclusions
The postnatal risk of SVT is related to the arrhythmia mechanism and prenatal treatment response. Of newborns without spontaneous SVT, TEPS may be useful to guide the need for postnatal treatment based on SVT inducibility.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 21 Apr 2022; epub ahead of print
Michel M, Renaud C, Chiu-Man C, Gross G, Jaeggi E
Heart Rhythm: 21 Apr 2022; epub ahead of print | PMID: 35462052
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Molecular and functional characterization of the mouse intracardiac nervous system.

Lizot G, Pasqualin C, Tissot A, Pagès S, Faivre JF, Chatelier A
Background
The intracardiac nervous system (ICNS) refers to clusters of neurons, located within the heart, which participate to the neuronal regulation of cardiac functions and which are involved in the initiation of cardiac arrhythmias. Therefore, deciphering its role in cardiac physiology and physiopathology is mandatory.
Objective
The aim of this study is to provide a phenotypic, electrophysiological and pharmacological characterization of the mouse ICNS, which is still poorly characterized.
Methods
Global cardiac innervation and phenotypic diversity were investigated using immunohistochemistry on cleared murine heart and on tissue sections. Patch clamp technique was used for electrophysiological and pharmacological characterization of isolated mouse intracardiac neurons.
Results
We have identified the expression of seven distinct neuronal markers within mouse ICNS, thus proving the neurochemical diversity of this network. Of note, it was the first time that the existence of neurons expressing the calcium binding protein calbindin, the neuropeptide Y (NPY) and the cocain and amphetamine regulated transcript (CART) peptide, was described in the mouse. Electrophysiological studies also revealed the existence of four different neuronal populations based on their electrical behavior. Finally, we showed that these neurons can be modulated by several neuromodulators.
Conclusion
This study showed that mouse ICNS presents a molecular and functional complexity similar to other species, and is therefore a suitable model to decipher the role of individual neuronal subtypes regarding the modulation of cardiac function and the initiation of cardiac arrhythmias.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 18 Apr 2022; epub ahead of print
Lizot G, Pasqualin C, Tissot A, Pagès S, Faivre JF, Chatelier A
Heart Rhythm: 18 Apr 2022; epub ahead of print | PMID: 35447308
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Clinical outcomes and predictors of complications in patients undergoing leadless pacemaker implantation.

Haddadin F, Majmundar M, Jabri A, Pecha L, ... Chelu MG, Deshmukh AJ
Background
Leadless pacemakers have emerged as a viable alternative for traditional transvenous pacemakers to reduce the risk of device-related complications.
Objective
The purpose of this study was to examine the real-world clinical outcomes and complications associated with the implantation of leadless pacemaker devices.
Methods
Using the National Readmission Database (NRD), we examined patient demographics, and in-hospital and 30-day procedural outcomes after leadless pacemaker implantation from 2016-2018. Our cohort comprised adults (≥18 years) with an ICD-10 procedural code for leadless pacemaker implantation.
Results
Our cohort included a total of 7821 patients who underwent leadless pacemaker implantation. Overall immediate procedure-related complications, as defined broadly in this study, occurred in 7.5% of patients. Pericardial effusion without the need for pericardiocentesis occurred in 1.9% of patients, with pericardiocentesis performed in 1.0%. Vascular complications occurred in 2.3% of patients; 0.33% required repair, and device dislodgment occurred in 0.51%. The most significant predictor for procedural complications was end-stage renal disease (odds ratio [OR] 1.65; 95% confidence interval [CI] 1.17-2.32; P = .004), congestive heart failure (OR 1.28; 95% CI 1.01-1.62; P = .04), and coagulopathy (OR 1.77; 95% CI 1.34-2.34; P <.001). All-cause readmission occurred in 17.9% of patients within 30 days from device implant, with 1.36% of readmissions being procedure related. At 30 days postimplant and after discharge, 0.25% of patients needed a new pacemaker, and 0.18% had pericardial complications.
Conclusion
In our large real-life cohort, we found the rate of serious complications after leadless pacemaker implantation to be relatively low and comparable to prior studies in a high-risk population with multiple comorbid conditions.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 18 Apr 2022; epub ahead of print
Haddadin F, Majmundar M, Jabri A, Pecha L, ... Chelu MG, Deshmukh AJ
Heart Rhythm: 18 Apr 2022; epub ahead of print | PMID: 35490710
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Early Trends in Leadless Pacemaker Implantation: Evaluating Nationwide In-Hospital Outcomes.

Vincent L, Grant J, Peñalver J, Ebner B, ... Goldberger JJ, Mitrani RD
Background
Single-chamber leadless intracardiac pacemaker (LICP) implantation was approved in 2016 in the United States. However, little is known regarding trends in real-world utilization and complication rates.
Objective
We sought to assess nationwide demographics, trends, and outcomes among hospitalizations with LICP implantation in the United States.
Methods
Using the National Inpatient Sample, we identified all hospitalizations with LICP or transvenous pacemaker implantation as a comparator between 2017-2019. We evaluated baseline patient characteristics, admitting diagnoses, procedural complications, length of stay, discharge disposition and all-cause mortality.
Results
The majority of LICP recipients were elderly (75.4 ± 12.8 years), male (55.2%) and White (76.8%) compared to Black (9.8%), or Hispanic (7.3%). Between 2017-2019, the average age increased along with the prevalence of heart failure, atrial fibrillation, and malignancy among recipients. Most hospitalizations were emergent (84.5%). Between 2017-2019, pooled procedural complications decreased significantly (10.8% vs. 7.9%, p < 0.001), primarily due to declining infection and device retrieval rates. In-hospital mortality also decreased significantly (8.2% vs. 4.2%, p < 0.001). History of cardiogenic shock or cardiac device infection were associated with greatest mortality or complication risk. Compared to transvenous pacemaker, LICP implantation was associated with lower complication rates (8.6% vs. 11.2%) but greater mortality (5.2% vs. 1.3%, p < 0.001).
Conclusion
Nationwide LICP implantations were performed in patients of increasing age, comorbidities, and acuity of illness. In-hospital mortality and procedure-related complications declined in the first three years following approval and may reflect improving operator experience. Increased mortality compared with transvenous pacemaker implant remains a concern.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 14 Apr 2022; epub ahead of print
Vincent L, Grant J, Peñalver J, Ebner B, ... Goldberger JJ, Mitrani RD
Heart Rhythm: 14 Apr 2022; epub ahead of print | PMID: 35430342
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

INCIDENCE OF NEW ONSET ATRIAL FIBRILLATION AFTER TRANSCATHETER PFO CLOSURE USING 15 YEARS OF ONTARIO ADMINISTRATIVE HEALTH DATA.

Oliva L, Huszti E, Hall R, Abrahamyan L, Horlick E
Background
Individuals with patent foramen ovale (PFO) routinely undergo transcatheter closure (TC) for secondary prevention of recurrent stroke. However, there has been some evidence suggesting that TC may increase the risk of new-onset atrial fibrillation (AF).
Objective
To evaluate the risk of new-onset AF following PFO closure and to explore predictors of AF development.
Methods
We created a retrospective cohort of all Ontarians over 18-years of age who received TC between October 2002 and December 2017 using administrative health data and the CorHealth cardiac registry. A Poisson regression determined event rates of AF and secondary outcomes such as stroke and mortality per 1,000 person-years. A multivariable Cox proportional hazards model identified predictors of new-onset AF following TC.
Results
Of 1,533 patients, 96 (6.26%) developed new-onset AF following PFO closure, over an average follow-up time of 8.2 years. Age >60 years (HR =2.82; CI:1,76-4.51; p < 0.001) and diabetes (HR=2.49; CI:1.48-4.18; p <0.001) were statistically significant, independent predictors of AF according to the Cox model.
Conclusions
The incidence of new-onset AF after PFO closure was relatively low. Having diabetes and age > 60 years were the most important factors associated with new-onset AF in this population.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 13 Apr 2022; epub ahead of print
Oliva L, Huszti E, Hall R, Abrahamyan L, Horlick E
Heart Rhythm: 13 Apr 2022; epub ahead of print | PMID: 35429648
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Permanent pacemaker implantation after valve and arrhythmia surgery in patients with pre-operative atrial fibrillation.

Kowalewski M, Pasierski M, Finke J, Kołodziejczak M, ... Suwalski P, Thoracic Research Centre
Background
Among patients referred for cardiac surgeries, atrial fibrillation (AF) is a common comorbidity and a risk factor for post-operative arrhythmias (such as sinus node dysfunction or atrioventricular heart blocks), including those requiring permanent pacemaker (PPM) implantation.
Objective
The current study aimed to evaluate the prevalence and long-term survival of post-operative PPM implantation in patients with pre-operative AF who underwent valve surgery with or without concomitant procedures.
Methods
Presented analysis pertains to the HEIST (HEart surgery In atrial fibrillation and Supraventricular Tachycardia) registry. During study period 11,949 patients underwent valvular (aortic, mitral or tricuspid valve replacement or repair) surgery and/or surgical ablation (SA) and were stratified according to post-operative PPM status.
Results
Permanent pacemaker implantation after surgery was necessary in 2.5% of patients, with a significant variation depending on the type of surgery (from 1.1% in mitral valve repair to 3.3% in combined mitral and tricuspid valve surgery). In a multivariate logistic regression model, tricuspid intervention (P<0.001), cardio-pulmonary bypass time (P=0.024) and endocarditis (P=0.014) were shown to be risk factors for PPM. Over long-term follow-up PPM was not associated with increased mortality as compared to no PPM: Hazard Ratio 0.96; 95% Confidence Intervals 0.77-1.19; P=0.679. Surgical ablation was not associated with PPM implantation; in the same time, SA improved survival regardless of PPM status (log rank P<0.001).
Conclusion
In patients with pre-operative AF, the need for PPM implantation after valve surgery or SA is not an infrequent outcome, with SA not affecting its prevalence but actually improving long-term survival.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 13 Apr 2022; epub ahead of print
Kowalewski M, Pasierski M, Finke J, Kołodziejczak M, ... Suwalski P, Thoracic Research Centre
Heart Rhythm: 13 Apr 2022; epub ahead of print | PMID: 35429649
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Heart Rhythm Society Atrial Fibrillation Centers of Excellence Study: A survey analysis of stakeholder practices, needs, and barriers.

Sandhu RK, Seiler A, Johnson CJ, Bunch TJ, ... Smith AM, Freeman J
Background
An integrated, coordinated, and patient-centered approach to atrial fibrillation (AF) care delivery may improve outcomes and reduce cost.
Objective
The purpose of this study was to gain a better understanding from key stakeholder groups on current practices, needs, and potential barriers to implementing optimal integrated AF care.
Methods
A series of comprehensive questionnaires were designed by the Heart Rhythm Society Atrial Fibrillation Centers of Excellence (CoE) Task Force to conduct surveys with physicians, advanced practice professionals, patients, and hospital administrators. Data collected focused on the following areas: access to care, stroke prevention, education, AF quality improvement, and AF CoE needs and barriers. Survey responses were collated and analyzed by the Task Force.
Results
The surveys identified 5 major unmet needs: (1) Standardized protocols, order sets, or care pathways in the emergency department or inpatient setting were uncommon (36%-42%). (2) All stakeholders agreed stroke prevention was a top priority; however, prior bleeding or risk of bleeding was the most frequent barrier for initiation. (3) Patients indicated that education on modifiable causes, AF-related complications, and lowering stroke risk is most important. (4) Less than half (43%) of the health care systems track patients with AF or treatment status. Patients reported that stroke and heart failure prevention and access to procedures were priority areas for an AF CoE. The most common barriers to implementing AF CoE identified by clinicians were administrative support (69%) and cost (52%); administrators reported physical space (43%).
Conclusion
On the basis of the findings of this study, the Task Force identified high priority areas to develop initiatives to aid the implementation of AF CoE.

Copyright © 2022 Heart Rhythm Society. All rights reserved.

Heart Rhythm: 12 Apr 2022; epub ahead of print
Sandhu RK, Seiler A, Johnson CJ, Bunch TJ, ... Smith AM, Freeman J
Heart Rhythm: 12 Apr 2022; epub ahead of print | PMID: 35428582
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Outcome of patients with early repolarization pattern and syncope.

Kamakura T, Gourraud JB, Clementy N, Maury P, ... Probst V, Sacher F
Background
Syncope in patients with an early repolarization (ER) pattern presents a challenge for clinicians as it has been identified as an indicator of a higher risk of life-threatening ventricular arrhythmias (VAs).
Objectives
This study aimed to analyze the outcome of patients with an ER pattern and syncope and to evaluate the factors predictive of VAs.
Methods
Over a period of 5 years, we enrolled 143 patients with an ER pattern and syncope in a multicenter prospective registry.
Results
After the initial examinations, 97 patients (67.8%) were implanted with a device allowing electrocardiogram monitoring, including 84 with an implantable loop recorder. During a mean follow-up period of 68 ± 34 months, we documented 16 arrhythmias presumably responsible for syncope (5 VAs, 10 bradycardias, and 1 supraventricular tachycardia). Additionally, recurrent syncope not associated with electrocardiogram documentation occurred in 16 patients (11.2%). The cause of syncope was identified in 23 of 97 patients with a monitoring device (23.8%). The 5-year incidence of VAs and arrhythmic events presumably responsible for syncope was 4.9% and 11.0%, respectively. Patients who developed VAs showed no prodromes or specific triggers at the time of syncope. Neither the presence of a family history of sudden cardiac death nor the previously reported high-risk electrocardiographic parameters differed between patients with and without VAs.
Conclusion
VAs occurred in 4.9% of patients with an ER pattern and syncope. Device implantation based on detailed history taking seems to be a reasonable strategy. Previously reported high-risk electrocardiographic patterns did not identify patients with VAs.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 05 Apr 2022; epub ahead of print
Kamakura T, Gourraud JB, Clementy N, Maury P, ... Probst V, Sacher F
Heart Rhythm: 05 Apr 2022; epub ahead of print | PMID: 35395407
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Atrial Fibrillation Mechanisms Before and After Pulmonary Vein Isolation Characterized by Non-Contact Charge Density Mapping.

Liu FZ, Zaman JAB, Ehdaie A, Xue YM, ... Shehata M, Wang X
Background
The interaction of pulmonary vein and putative non-pulmonary triggers of atrial fibrillation (AF) remains unclear, and has yet to translate into patient tailored ablation strategies.
Objective
To use non-contact mapping to detail the global conduction patterns in paroxysmal and persistent AF and how they are modified during pulmonary vein ablation.
Methods
40 patients at atrial fibrillation ablation underwent mapping using a non-contact catheter (AcQMap, Acutus Medical Inc) before and after pulmonary vein isolation (PVI). Propagation history maps were analysed post-procedure for each patient to categorise conduction patterns into Focal, Organised reentrant and Disorganized patterns.
Results
Activation patterns identified by using a non-contact mapping system can be sub-classified from three main patterns into subtypes (MacroReentrant and LocalisedReentrant subtypes, Disorganized 1 and Disorganized 2 subtypes). Persistent AF demonstrated more D-Patterns, and less O-Patterns and F-Patterns than paroxysmal AF. In addition, PAF patients inducible after PVI demonstrated a greater number and higher prevalence of MR subtypes than those non-inducible. PVs remained the critical region and included almost one third of all patterns across any AF-types. PVI was effective to eliminate PV-related functional phenotypes, and impacted on recurrence with other patterns.
Conclusion
Activation patterns identified using AcQMap can be classified into three main patterns (F-Patterns, O-Patterns and D-Patterns) as well as subtypes (MR and LR subtype, D1 and D2 subtype). PerAF was different from PAF in demonstrating a greater region number and prevalence of D-Patterns, but lower region number and prevalence of O-Patterns and F-Patterns.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 02 Apr 2022; epub ahead of print
Liu FZ, Zaman JAB, Ehdaie A, Xue YM, ... Shehata M, Wang X
Heart Rhythm: 02 Apr 2022; epub ahead of print | PMID: 35381379
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Lower body muscle preactivation and tensing mitigate symptoms of initial orthostatic hypotension in young females.

Sheikh NA, Ranada S, Lloyd M, McCarthy D, ... Runté M, Raj SR
Background
Initial orthostatic hypotension (IOH) is a form of orthostatic intolerance defined by a transient decrease in blood pressure upon standing. Current clinical recommendations for managing IOH includes standing up slowly or lower body muscle tensing (TENSE) after standing. Considering that IOH is likely due to a large muscle activation response resulting in excessive vasodilation with a refractory period (<2 minutes), we hypothesized that preactivating lower body muscles (PREACT) before standing would reduce the drop in mean arterial pressure (MAP) upon standing and improve presyncope symptoms.
Objective
The purpose of this study was to provide IOH patients with effective symptom management techniques.
Methods
Study participants completed 3 sit-to-stand maneuvers, including a stand with no intervention (Control), PREACT, and TENSE. Continuous heart rate and beat-to-beat blood pressure were measured. Stroke volume and cardiac output were then estimated from these waveforms.
Results
A total of 24 female IOH participants (mean ± SD: 32 ± 8 years) completed the study. The drops in MAP following PREACT (-21 ± 8 mm Hg; P <.001) and TENSE (-18 ± 10 mm Hg; P <.001) were significantly reduced compared to Control (-28 ± 10 mm Hg). The increase in cardiac output was significantly larger following PREACT (2.6 ± 1 L/min; P <.001) but not TENSE (1.9 ± 1 L/min; P = .2) compared to Control (1.4 ± 1 L/min). The Vanderbilt Orthostatic Symptom Score following PREACT (9 ± 8 au; P = .033) and TENSE (8 ± 8 au; P = .046) both were significantly reduced compared to Control (14 ± 9 au).
Conclusion
Both the drop in MAP and symptoms upon standing improved with either PREACT or TENSE. These maneuvers provide novel symptom management techniques for patients with IOH.

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

Heart Rhythm: 31 Mar 2022; 19:604-610
Sheikh NA, Ranada S, Lloyd M, McCarthy D, ... Runté M, Raj SR
Heart Rhythm: 31 Mar 2022; 19:604-610 | PMID: 35365286
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Effect of radiofrequency and ethanol ablation on epicardial conduction through the vein of Marshall: How to detect and manage epicardial connection across the mitral isthmus.

Kawaguchi N, Tanaka Y, Okubo K, Tachibana S, ... Sasano T, Takahashi A
Background
Vein of Marshall (VOM), surrounded by the Marshall bundle (MB), behaves as an epicardial connection bypassing the mitral isthmus. The influence of radiofrequency ablation and VOM ethanol infusion (VOM-EI) on epicardial MB conduction remains unclear.
Objective
This study aimed to evaluate MB conduction status during mitral isthmus ablation.
Methods
Of 57 consecutive patients undergoing mitral isthmus ablation, 50 with electrode catheter cannulation into the VOM were analyzed. MB conduction was investigated by evaluating electrograms inside the VOM. Endocardial ablation was initially performed, followed by ablation inside the coronary sinus (CS), if required. Selective VOM-EI was performed if the MB potentials still exhibited early activation after radiofrequency ablation, suggesting the presence of MB connection bridging the mitral isthmus.
Results
VOM electrograms composed of near-field MB and far-field left atrial potentials were recorded in all patients. Solely with endocardial ablation, 33 patients (66%) achieved entire mitral isthmus block, and 43 patients (86%) achieved an epicardial MB conduction block. MB potentials exhibited early activation in the remaining seven (14%), even after requiring CS ablation. Then, VOM-EI was performed. Elimination of MB potentials was verified by electrode catheter re-insertion after VOM-EI. Mitral isthmus conduction was successfully blocked during VOM-EI in four patients and during additional radiofrequency ablation in the remaining three. All patients finally achieved entire mitral isthmus block.
Conclusions
MB is effectively ablated by radiofrequency ablation. Continuous evaluation of MB conduction can reveal epicardial conduction and ablation effect. A residual MB epicardial connection is relatively rare but can be ablated by VOM-EI.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 31 Mar 2022; epub ahead of print
Kawaguchi N, Tanaka Y, Okubo K, Tachibana S, ... Sasano T, Takahashi A
Heart Rhythm: 31 Mar 2022; epub ahead of print | PMID: 35367659
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

The impact of heart rate circadian rhythm on in-hospital mortality in stroke and critically ill patients: insights from the eICU Collaborative Research Database.

Yang Z, Li Z, He X, Yao Z, ... Gao C, Chen J
Background
Data showing the impact of dysregulated heart rate circadian rhythm in stroke and critically ill patients are scarce.
Objective
The purpose of this study was to investigate whether the circadian rhythm of heart rate was an independent risk factor for in-hospital mortality in stroke and critically ill patients.
Methods
Study patients from the recorded eICU Database were included in the current analyses. Three variables, Mesor, Amplitude, and Peak time were used to evaluate the heart rate circadian rhythm. The incremental value of circadian rhythm variables in addition to Acute Physiology and Chronic Health Evaluation (APACHE) IV score to predict in-hospital mortality was also explored.
Results
A total of 6,201 Patients whose heart rate have cosinor rhythmicity. After adjustments, Mesor per 10 beats per min (bpm) increase was associated with a 1.18-fold (95%CI: 1.12, 1.25, P<0.001) and Amplitude per 5 bpm was associated with a 1.17-fold (95%CI: 1.07, 1.27, P<0.001) increase in the risk of in-hospital mortality, respectively. The risk of in-hospital mortality was highest in patients who had Peak time reached between 12:00-18:00 (OR: 1.35, 95%CI: 1.06, 1.72, P=0.015). Compared with APACHE IV score only (c-index=0.757), combining APACHE IV score and circadian rhythm variables of heart rate (c-index=0.766) was associated with increased discriminative ability (P=0.003).
Conclusion
Circadian rhythm of heart rate is an independent risk factor of the in-hospital mortality in stroke and critically ill patients. Including circadian rhythm variables regarding heart rate might increase the discriminative ability of the risk score to predict the prognosis of patients.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 31 Mar 2022; epub ahead of print
Yang Z, Li Z, He X, Yao Z, ... Gao C, Chen J
Heart Rhythm: 31 Mar 2022; epub ahead of print | PMID: 35367661
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

R-on-T and the Initiation of Reentry Revisited: Integrating Old and New Concepts.

Qu Z, Liu MB, Olcese R, Karagueuzian H, ... Chen PS, Weiss JN
Initiation of reentry requires two factors: 1) a triggering event, most commonly focal excitations such as premature ventricular complexes (PVCs), and 2) a vulnerable substrate with regional dispersion of refractoriness and/or excitability, such as occurs during the T-wave of the electrocardiogram when some areas of the ventricle have repolarized and recovered excitability but others have not. When the R-wave of a PVC coincides in time with the T-wave of the previous beat, this timing can lead to unidirectional block and initiation of reentry, known as the R-on-T phenomenon. Classically, the PVC triggering reentry has been viewed arising focally from one region and propagating into another region whose recovery is delayed, resulting in unidirectional conduction block and reentry initiation. However, more recent evidence indicates that PVCs also can arise from the T-wave itself. In the latter case, the PVC initiating reentry is not a separate event from the T-wave, but rather is causally generated from the repolarization gradient that manifests as the T-wave. We call the former as \"R-to-T\" mechanism and the latter as \"R-from-T\" mechanism, which are initiation mechanisms distinct from each other. Both are important components of the R-on-T phenomenon and need to be taken into account in designing antiarrhythmic strategies. Strategies targeting suppression of triggers alone or vulnerable substrate alone may be appropriate in some instances, but not in others. Preventing R-from-T arrhythmias requires suppressing the underlying dynamical tissue instabilities responsible for producing both triggers and substrate vulnerability simultaneously. The same principles are likely to apply to supraventricular arrhythmias.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 29 Mar 2022; epub ahead of print
Qu Z, Liu MB, Olcese R, Karagueuzian H, ... Chen PS, Weiss JN
Heart Rhythm: 29 Mar 2022; epub ahead of print | PMID: 35364332
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Atrioventricular junction ablation in patients with conduction system pacing leads: A comparison of His-bundle vs left bundle branch area pacing leads.

Pillai A, Kolominsky J, Koneru JN, Kron J, ... Verma A, Ellenbogen KA
Background
Single-center studies have shown feasibility of conduction system pacing (CSP) via His-bundle pacing (HBP) or left bundle branch area pacing (LBBAP) in atrial fibrillation (AF) patients undergoing atrioventricular junction ablation (AVJA).
Objective
The purpose of this study was to compare outcomes in patients with HBP and LBBAP leads undergoing AVJA.
Methods
Consecutive patients with CSP leads referred for AVJA between October 2014 and May 2021 were included. Pacing lead characteristics, procedural characteristics, complications, and long-term outcomes were assessed.
Results
One hundred five AVJA procedures (55 HBP, 50 LBBAP) were performed in 98 patients (48 HBP, 50 LBBAP). The acute success rate of the AVJA procedure was 94% vs 100% (P = .11) in HBP vs LBBAP groups. Seven (14%) redo AVJA procedures were required in the HBP group. Mean procedural time (44 ± 24 min vs 34 ± 16 min; P = .02) and mean fluoroscopy time (16 ± 18 min vs 7 ± 6 min; P <.001) were significantly longer in the HBP vs LBBAP group. An acute rise in threshold was noted in 8 cases (14.5%), and 4 (8%) developed exit block after AVJA in HBP patients. Chronic HBP threshold ≥2.5 V was seen in 23 patients (48%), and 4 (8%) HBP leads were deactivated. CSP preserved ejection fraction (EF) in the overall cohort (N = 70; 53% ± 10% vs 55% ± 10%; P = .09) and significantly improved in those with reduced EF <50% at baseline (N = 16; 37% ± 7.6% vs 46% ± 13%; P = .02).
Conclusion
AVJA in the presence of an LBBAP lead is associated with a higher success rate and fewer acute and chronic lead-related complications. CSP with either HBP or LBBAP preserves left ventricular systolic function in patients with refractory atrial fibrillation post AVJA.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 26 Mar 2022; epub ahead of print
Pillai A, Kolominsky J, Koneru JN, Kron J, ... Verma A, Ellenbogen KA
Heart Rhythm: 26 Mar 2022; epub ahead of print | PMID: 35351624
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

SCN5A overlap syndromes: An open-minded approach.

Porretta AP, Probst V, Bhuiyan ZA, Davoine E, ... Superti-Furga A, Pruvot E
SCN5A overlap syndromes are clinical entities that express a phenotype combining aspects of different canonical SCN5A-related arrhythmia syndromes or a variable arrhythmic phenotype among individuals carrying the same SCN5A mutation. Here we review the literature addressing SCN5A overlap syndromes as well as the principal mechanisms currently proposed. Among others, a multifactorial determination encompassing an interaction between SCN5A variant(s), other genetic polymorphisms, and possibly environmental factors seems the most plausible hypothesis.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 26 Mar 2022; epub ahead of print
Porretta AP, Probst V, Bhuiyan ZA, Davoine E, ... Superti-Furga A, Pruvot E
Heart Rhythm: 26 Mar 2022; epub ahead of print | PMID: 35351625
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Termination of macroreentrant atrial arrhythmias by pacing stimuli without global propagation.

Jain R, Jain R, Barmeda M, Shirazi JT, Abualsuod A, Miller JM
Background
Electrical stimulation during ventricular tachycardia resulting in tachycardia termination without global propagation (TWGP) is a well-recognized phenomenon. However, there is a paucity of literature showing a similar phenomenon in atrial arrhythmias.
Objective
The purpose of the study was to evaluate the significance of TWGP in atrial arrhythmias.
Methods
Electrophysiological studies performed from 2000 to 2019 at Methodist Hospital, Indiana University were reviewed retrospectively. Thirty-four patients were identified in whom stimulation during atrial tachycardia/flutter resulted in TWGP.
Results
Of the 34 patients, 12 (29%) had cavotricuspid isthmus (CTI)-dependent atrial flutter and 22 (71%) had other atrial arrhythmias during which TWGP was seen. Mean age of the population was 53 ± 13 years; and 68% were male. Previous catheter ablation for atrial fibrillation, atrial flutter, or other atrial tachyarrhythmias had been performed in 70.5%, and 44% previously had undergone cardiac surgery involving the atria. Congenital heart disease was present in 20.5%; 3 patients were status post lung transplant. Mean cycle length of atrial arrhythmia in which TWGP was seen was 317 ± 76 ms. The sites at which TWGP was seen reproducibly were highly specific for successful termination of the arrhythmias with radiofrequency energy. The arrhythmia circuits were 12 CTI-dependent atrial flutter, 11 left atrial macroreentrant atrial tachycardia (MRAT), 1 involving both left and right atria, and 8 were other right atrial MRAT.
Conclusion
Termination of macroreentrant atrial arrhythmias by pacing stimuli without global propagation identifies a narrow diastolic isthmus at which catheter ablation is highly effective.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 24 Mar 2022; epub ahead of print
Jain R, Jain R, Barmeda M, Shirazi JT, Abualsuod A, Miller JM
Heart Rhythm: 24 Mar 2022; epub ahead of print | PMID: 35341994
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Exercise training in heart failure with reduced ejection fraction and permanent atrial fibrillation: A randomized clinical trial.

Alves LS, Bocchi EA, Chizzola PR, Castro RE, ... Andreta CRL, Guimarães GV
Background
Heart failure (HF) associated with atrial fibrillation increases patients\' physical inactivity, worsening their clinical condition and mortality. Exercise training is safe and has clear benefits in HF. However, little is known about the effects of exercise training on patients with HF with reduced ejection fraction and permanent atrial fibrillation (HFAF).
Objective
The purpose of this study was to test the hypothesis that exercise training improves functional capacity, cardiac function, and quality of life in patients with HFAF.
Methods
This randomized clinical trial was conducted at the Heart Institute. Patients with HFAF, left ventricular ejection fraction ≤40%, and resting heart rate (HR) ≤80 beats/min were included in the study. Cardiopulmonary testing, echocardiography, autonomic, and quality of life assessment were performed before and after the 12-week protocol period.
Results
Twenty-six patients (mean age 58 ± 1 years) were randomized to exercise training (HFAF-trained group; n = 13) or no training (HFAF-untrained group; n = 13). At baseline, no differences between the groups were found. Exercise improved peak oxygen consumption, slope of ventilation per minute/carbon dioxide production, and quality of life. The HFAF-trained group had significantly decreased resting HR (from 73 ± 2 to 69 ± 2 beats/min; P = .02) and recovery HR (from 148 ± 11 to 128 ± 9 beats/min; P = .001). Concomitantly, left ventricular ejection fraction increased (from 31% ± 1% to 36% ± 0.9%; P = .01), left atrial dimension decreased (from 52 ± 1.2 to 47 ± 1 mm; P = .03), and left ventricular end-systolic volume and left ventricular end-diastolic volume deceased (from 69 ± 2 to 64 ± 1.8 mL/m2 and from 99 ± 2.1 to 91 ± 2 mL/m2, respectively; P < .05). No changes were observed in the HFAF-untrained group.
Conclusion
Exercise training can improve exercise capacity, quality of life, and cardiac function in patients with HF with reduced ejection fraction and permanent atrial fibrillation.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 21 Mar 2022; epub ahead of print
Alves LS, Bocchi EA, Chizzola PR, Castro RE, ... Andreta CRL, Guimarães GV
Heart Rhythm: 21 Mar 2022; epub ahead of print | PMID: 35331961
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Skin sympathetic nerve activity in patients with chronic orthostatic intolerance.

Lee A, Liu X, Rosenberg C, Borle S, ... Merz NB, Peng-Sheng Chen C
Background
Chronic orthostatic intolerance (OI) is characterized by the development of tachycardia and other symptoms when assuming an upright body position.
Objective
The purpose of this study was to test the hypothesis that skin sympathetic nerve activity (SKNA) bursts are specific symptomatic biomarkers in patients with chronic OI.
Methods
We used an electrocardiogram monitor with a built-in triaxial accelerometer to simultaneously record SKNA and posture in ambulatory participants. Study 1 compared chronic OI (14 women and 2 men; mean age 35 ± 10 years) with reference control participants (14 women; mean age 31 ± 6 years). Study 2 included 17 participants with chronic OI (15 women and 2 men; mean age 39 ± 12 years) not yet treated with ivabradine, pyridostigmine, or β-blockers.
Results
In study 1, there were 124 episodes (8 ± 4 per participant) of postural changes, with 11 episodes (8.9%) associated with symptoms. In comparison, 0 of 104 postural changes (7 ± 3 per participant) in controls were symptomatic (P = .0011). In participants with chronic OI, the SKNA bursts associated with symptoms had higher burst frequencies, longer burst durations, and larger mean burst areas than did bursts during asymptomatic periods. However, SKNA bursts and tachycardia were asymptomatic in controls. We analyzed 110 symptomatic episodes in study 2 (6 ± 5 per participant). Among them, 98 (89.1%) followed at least 1 SKNA burst. In comparison, only 41 (37.3%) had heart rate exceed 100 beats/min 1 minute before symptom onset (P < .0001).
Conclusion
SKNA bursts are a highly specific, albeit insensitive, symptomatic biomarker for chronic OI.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 17 Mar 2022; epub ahead of print
Lee A, Liu X, Rosenberg C, Borle S, ... Merz NB, Peng-Sheng Chen C
Heart Rhythm: 17 Mar 2022; epub ahead of print | PMID: 35307584
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

CHARACTERIZATION OF THE RIGHT VENTRICULAR SUBSTRATE PARTICIPATING IN POST INFARCTION VENTRICULAR TACHYCARDIA.

Walsh KA, Daw JM, Lin A, Guandalini G, ... Marchlinski FE, Santangeli P
Background
The right ventricle (RV) is uncommonly implicated in post-infarction ventricular tachycardia (VT). The prevalence and features of RV substrate participating in post-infarction VT are undefined.
Objectives
To characterize critical RV substrate (CRVS) involvement in patients with post-infarction VT.
Methods
We retrospectively reviewed 1279 patients with post-infarction VT undergoing catheter ablation at our center from January 2000 through May 2020. Cases with CRVS defined by conclusive demonstration of participation in VT with activation, entrainment and/or pace mapping during sinus rhythm were identified.
Results
CRVS was identified in 27/1279 (2.1%), age 65±13 years, 96% males, median LV EF 25%, 93% with LBBB morphology VT. CRVS was identified by RV activation and/or entrainment mapping (n=19) or by presence of low-voltage abnormal electrograms with excellent pace-map for the targeted VT and non-inducibility following ablation (n=8). VT termination during RV ablation occurred in 15 patients. After a median follow-up of 20 months (interquartile range 9-53 months) and a median of 2 procedures (interquartile range 1-3), 22/27 (80%) patients had no VT recurrence and 11 (41%) died.
Conclusion
The RV contains critical substrate elements of post-infarction VT in at least 2.1% of cases. RV mapping should be considered in cases where LV mapping fails to demonstrate adequate targets, particularly in patients with LBBB morphology VT.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 08 Mar 2022; epub ahead of print
Walsh KA, Daw JM, Lin A, Guandalini G, ... Marchlinski FE, Santangeli P
Heart Rhythm: 08 Mar 2022; epub ahead of print | PMID: 35276321
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Intramyocardial mapping of ventricular premature depolarizations via septal venous perforators: Differentiating the superior intraseptal region from left ventricular summit origins.

Guandalini GS, Santangeli P, Schaller R, Pothineni NVK, ... Marchlinski FE, Garcia FC
Background
The intramyocardial aspect of the left ventricular summit (LVS) can be mapped by advancing a unipolar guidewire into septal perforator branches of the anterior intraventricular vein (AIV).
Objective
To differentiate between ventricular premature depolarizations (VPDs) with a basal superior intraseptal (SIS) site of origin and those originating from the epicardial LVS using septal intramyocardial mapping.
Methods
A retrospective cohort of patients with suspected LVS VPDs who underwent SIS unipolar mapping were reviewed for their clinical characteristics, mapping findings and procedural outcomes.
Results
SIS mapping was successful in 44 out of 47 cases (93.6%). VPD origin was SIS (defined as earliest activation from intraseptal wire) in 20 patients (45.5%, median 23ms pre-QRS). Procedural success was similar in patients with (group 1) and without (group 2) SIS origin (respectively, 84% vs. 87.5%, p = 0.842). Of the 10 patients in group 1 without pre-systolic endocardial activation, 5 (11.3% of all 44 cases) were successfully ablated from the LV endocardium, using an anatomical approach targeting the endocardium closest to the earliest intraseptal activation site.
Conclusion
A significant proportion, 45.5%, of VPDs that appear to arise from the LV summit can be demonstrated to have a SIS origin using septal perforator venous mapping. A significant minority (11.3%) of these can be ablated from the endocardium by targeting from an anatomic vantage point closest to the earliest intraseptal activation site. The described strategy may help differentiate true LVS VPDs from those with SIS sites of origin.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 08 Mar 2022; epub ahead of print
Guandalini GS, Santangeli P, Schaller R, Pothineni NVK, ... Marchlinski FE, Garcia FC
Heart Rhythm: 08 Mar 2022; epub ahead of print | PMID: 35278700
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Remote and Wearable ECG Devices with Diagnostic Abilities in Adults: A State-of-the-Science Scoping Review.

Bouzid Z, Al-Zaiti SS, Bond R, Sejdic E
The electrocardiogram (ECG) records the electrical activity in the heart in real-time, providing an important opportunity to detecting various cardiac pathologies. The 12-lead ECG currently serves as the \"standard\" ECG acquisition technique for diagnostic purposes for many cardiac pathologies other than arrhythmias. However, the technical aspects of acquiring a 12-lead ECG are not easy and its usage is currently restricted to trained medical personnel, limiting the scope of its usefulness. Remote and wearable ECG devices have attempted to bridge this gap by enabling patients to take their own ECG using a simplified method at the expense of a reduced number of leads, usually a single-lead ECG. In this review article, we summarize the studies which investigate the use of remote ECG devices and their clinical utility in diagnosing cardiac pathologies. Eligible studies discussed FDA-cleared, commercially available devices that were validated on an adult population. We summarize technical logistics of signal quality and device reliability, dimensional and functional features, and diagnostic value. In summary, our synthesis shows that reduced-set ECG wearables have huge potential for long-term monitoring, particularly if paired with real-time notification techniques. Such capabilities make them primarily useful for abnormal rhythm detection and there is sufficient evidence that a remote ECG device can be more superior to traditional 12-lead ECG in diagnosing specific arrhythmias such as atrial fibrillation. However, this review identifies important challenges faced by this technology, highlighting the limited availability of clinical research examining their usefulness.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 07 Mar 2022; epub ahead of print
Bouzid Z, Al-Zaiti SS, Bond R, Sejdic E
Heart Rhythm: 07 Mar 2022; epub ahead of print | PMID: 35276320
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Age-related differences and associated mid-term outcomes of subcutaneous implantable cardioverter defibrillators: a propensity-matched analysis from a multicenter European registry.

Gulletta S, Gasperetti A, Schiavone M, Vogler J, ... Forleo GB, Tilz R
Background
A few limited case series have shown that the S-ICD system is safe in teenagers and young adults, but a large-scale analysis is currently lacking.
Objectives
To compare mid-term device-associated outcomes in a large real-world cohort of S-ICD patients, stratified by age at implantation.
Methods
Two propensity-matched cohorts of teenagers + young adults (≤ 30-year-old) and adults (> 30-year-old) were retrieved from the ELISIR registry. The primary outcome was the comparison of the inappropriate shock rate; complications, freedom from sustained ventricular arrhythmias, overall and cardiovascular mortality were deemed secondary outcomes.
Results
Teenagers + young adults represented 11.0% of the entire cohort. Two propensity-matched groups of 161 patients each were used for the analysis; median follow-up was 23.1 [13.2-40.5] months. 15.2% patients experienced inappropriate shocks and 9.3% device related complications were observed, with no age-related differences in inappropriate shocks (16.1% vs 14.3%; p=0.642) and complication rates (9.9% vs 8.7%; p=0.701). At univariate analysis, young age was not associated with increased rates of inappropriate shocks (HR 1.204 [0.675-2.148]: p=0.529). At multivariate analysis, the use of SMART pass algorithm was associated to a strong reduction in inappropriate shocks (aHR 0.292 [0.161-0.525]; p<0.001), while ARVC was associated with higher rates of inappropriate shocks (aHR 2.380 [1.205-4.697]; p=0.012).
Conclusion
In a large multicentered registry of propensity-matched patients, the use of S-ICD in teenagers/young adults resulted safe and effective. The rates of inappropriate shocks and complications between cohorts were not significantly different. The only predictor of increased inappropriate shocks was a diagnosis of ARVC.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 03 Mar 2022; epub ahead of print
Gulletta S, Gasperetti A, Schiavone M, Vogler J, ... Forleo GB, Tilz R
Heart Rhythm: 03 Mar 2022; epub ahead of print | PMID: 35257974
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Prognostic impact of permanent pacemaker implantation following transcatheter aortic valve replacement.

Sharobeem S, Boulmier D, Leurent G, Bedossa M, ... Le Breton H, Auffret V
Background
Conduction disturbances requiring permanent pacemaker implantation (PPI) remain a common complication of transcatheter aortic valve replacement (TAVR).
Objectives
To determine the prognostic impact of PPI following TAVR, according to the timing of implantation relative to TAVR.
Methods
A total of 1199 patients (median age: 83 years old [78-86], 45.8% female) were included in the analysis, among whom 894 had no PPI, 130 had a previous PPI, 116 received in-hospital PPI, and 59 received PPI during follow-up. Median follow-up was 2.94 (1.42-4.32 years) years. The primary outcome was the composite of all-cause mortality and hospitalization for heart failure.
Results
PPI during follow-up was associated with a higher occurrence of the primary outcome (hazard ratio [HR]: 2.11, 95% confidence interval [CI]: 1.39-3.20) whereas previous and in-hospital PPI were not (HR: 0.96, 95%CI: 0.71-1.29, and HR:1.26, 95%CI: 0.88-1.81, respectively). PPI during follow-up associated with a higher risk of hospitalization for heart failure (sub HR: 3.21, 95%CI: 2.02-5.11) while this relation was only borderline significant for previous PPI (sub HR: 1.51, 95%CI: 0.99-2.29). In contrast, there was no relationship between in-hospital PPI and the subsequent risk of hospitalization for heart failure.
Conclusions
Previous PPI and in-hospital PPI had no long-term prognostic impact on the risk of all-cause mortality and hospitalization for heart failure, whereas PPI during follow-up associated with a higher risk of hospitalization for heart failure. The present study questions the deleterious influence of periprocedural post-TAVR PPI, which has previously been suggested by certain studies.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 03 Mar 2022; epub ahead of print
Sharobeem S, Boulmier D, Leurent G, Bedossa M, ... Le Breton H, Auffret V
Heart Rhythm: 03 Mar 2022; epub ahead of print | PMID: 35257975
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Transvenous Laser Lead Extraction in Patients with Congenital Complete Heart Block.

Darden D, Boateng BA, Tseng AS, Alshawabkeh L, ... Cha YM, Birgersdotter-Green U
Background
Data is lacking on lead management in patients with congenital complete heart block (CCHB) with cardiac implantable electronic devices (CIED).
Objective
This analysis sought to describe the natural history and outcomes in patients with CCHB with CIEDs undergoing transvenous lead extraction (TLE).
Methods
Data on all attempted TLE procedures in patients with CCHB at two institutions between 2011 and 2021 were collected from a retrospective registry.
Results
Overall, 16 patients (mean age at transvenous device implant: 13.8±4.7 years) were included. Before TLE, patients underwent an average of 2.25±1.3 generator changes, 3 (19%) underwent cardiac resynchronization therapy upgrade, and 7 (44%) underwent a lead revision with subsequently abandoned leads. Mean patient age at TLE was 34.4±9.4 years with a mean duration of lead implant of 19.2±6.9 years. Lead malfunction (n=11, 69%) and infection (n=5, 31%) were the most common indications for TLE. A total of 38 leads were removed with complete procedural success achieved in 14/16 (87.5%). Two (12.5%) major complications occurred, including right ventricular laceration and superior vena cava tear requiring sternotomies. All patients survived at one year follow-up.
Conclusion
Patients with CCHB represent a unique cohort highlighted by several generator changes, lead revisions, and abandoned leads at a young age, along with a long duration of lead dwelling time and a high prevalence of lead malfunction requiring TLE. There may be a high risk of major complications during TLE, suggesting TLE should only be performed in experienced centers. Larger studies are needed to confirm these findings.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 03 Mar 2022; epub ahead of print
Darden D, Boateng BA, Tseng AS, Alshawabkeh L, ... Cha YM, Birgersdotter-Green U
Heart Rhythm: 03 Mar 2022; epub ahead of print | PMID: 35257976
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Sex-related differences in the prognosis of patients with cardiac sarcoidosis treated with cardiac resynchronization therapy.

Nakasuka K, Ishibashi K, Hattori Y, Mori K, ... Ohte N, Kusano K
Background
Past studies showed the sex-related difference in the efficacy of cardiac resynchronization therapy (CRT). However, the data in cardiac sarcoidosis (CS) are limited.
Objective
To assess the sex-related prognostic differences in CS patients with CRT.
Methods
This multicenter CS survey included 430 patients (295 females) who met the diagnostic criteria of CS. Patients were divided into those treated with primary CRT or upgraded CRT from the pacemaker (CRT group, n=73) and others (control group, n=357). Sex differences in the incidence of all-cause death, heart failure (HF) death including heart transplantation, ventricular arrhythmia events (VAEs) (sudden death, appropriate device therapy), cardiac adverse events (CAEs) (HF death, VAEs), changes in serum brain natriuretic peptide (BNP) levels, and left ventricular ejection fraction (LVEF) over the follow-up were analyzed.
Results
During the median follow-up of 5.2 years, males, but not females, in the CRT group had significantly worse all-cause mortality than patients in the control group (p<0.001). In the CRT group, there was no significant sex-related difference in the incidence of HF death; however, females had significantly better VAEs- and CAEs-free survival than males (p=0.033, p=0.008, respectively). Multivariate analysis in the CRT group showed that female sex (hazard ratio 0.37, 95% confidence interval 0.15-0.89; p=0.026) independently predicted freedom from CAEs. During the follow-up, the BNP levels were significantly improved in all groups. LVEF was maintained in females with CRT.
Conclusions
In CS patients with CRT, HF death-free survival was similar between sexes. However, females exhibited better VAEs- and CAEs-free survival than males.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 03 Mar 2022; epub ahead of print
Nakasuka K, Ishibashi K, Hattori Y, Mori K, ... Ohte N, Kusano K
Heart Rhythm: 03 Mar 2022; epub ahead of print | PMID: 35257978
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Patterns of Care for First-detected Atrial Fibrillation: Insights from the Get With The Guidelines Atrial Fibrillation Registry.

Kir D, Zhang S, Kaltenbach LA, Fonarow GC, ... Piccini JP, Desai NR
Background
Despite multiple trials comparing rate with rhythm control, there is no consensus on optimal management of first-detected atrial fibrillation (AF).
Objective
We analyzed current patterns of care for first-detected AF in the nationwide Get With The Guidelines®- Atrial Fibrillation Registry
Methods:
Patients hospitalized with first-detected AF from 2013-19 were included and a descriptive analysis was performed comparing planned rate vs rhythm control. Multivariable logistic regression analysis was performed to identify predictors for choosing rhythm over rate control.
Results
Among 86,759 patients with AF, 17.8% (15,473) had first-detected AF, 11,685 patients were included from 126 sites. Overall, 51.3% of patients were treated with rate control, and 48.7% with rhythm control at admission. Patients with planned rhythm control had a shorter length of stay and were more likely to be discharged home than a facility. A higher percentage of patients with planned rhythm control were discharged on anticoagulation compared to planned rate control (75.6% vs 70.9%) despite a higher underlying stroke risk in the rate control group (higher median CHA2DS2VASc-score (4; Q1-Q3 2-5 vs 3; Q1-Q32-4; p<0.001). While Hispanic ethnicity, Medicaid insurance, age >70 years, and liver disease decreased the likelihood of rhythm control, factors like heart failure, stroke, or prior bleeding diathesis had no association with the chosen treatment strategy.
Conclusions
Less than half of the patients with first-detected AF receive rhythm control at admission. Given recent trial results, further studies should assess the long-term impact of rhythm control on patients\' symptoms and quality of life, cardiovascular morbidity, and mortality.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 01 Mar 2022; epub ahead of print
Kir D, Zhang S, Kaltenbach LA, Fonarow GC, ... Piccini JP, Desai NR
Heart Rhythm: 01 Mar 2022; epub ahead of print | PMID: 35247626
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Successful Avoidance of Superior Vena Cava Injury During Transvenous Lead Extraction Utilizing Tandem Femoral-Superior Approach.

Muhlestein JB, Dranow E, Chaney J, Navaravong L, Steinberg BA, Freedman RA
Background
Transvenous pacemaker and defibrillator lead extraction is a higher risk procedure with variation in preferred technique. A frequently fatal complication of this procedure is perforation of the superior vena cava. We have developed a tandem femoral-superior technique which incorporates snaring of targeted leads from a femoral approach combined with use of a rotational cutting sheath advanced over the lead from the subclavian vein.
Objective
We sought to evaluate the safety and efficacy of a tandem femoral-superior approach to lead extraction.
Methods
Consecutive patients undergoing transvenous extraction of at least 1 pacemaker or defibrillator lead with implant duration >1 year in which a tandem femoral-superior technique was used as the initial extraction strategy were included. The registry spanned 2010-2018 and consisted of procedures performed by a single primary operator.
Results
A total of 131 patients were included. A total of 267 leads with mean implant duration of 9.8 years, including 90 (33.7%) defibrillator leads, were targeted for extraction. No superior vena cava perforation or other vascular damage occurred. Clinical procedural success was achieved in 96.2 % of cases. There were 5 major complications (3.8% of patients) with 3 being pericardial effusion requiring intervention. There were no deaths.
Conclusion
A tandem femoral-superior approach to lead extraction effectively eliminated superior vena cava injury. This is a safe and effective technique for transvenous lead extraction.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 28 Feb 2022; epub ahead of print
Muhlestein JB, Dranow E, Chaney J, Navaravong L, Steinberg BA, Freedman RA
Heart Rhythm: 28 Feb 2022; epub ahead of print | PMID: 35245690
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

A phenotype-enhanced variant classification framework to decrease the burden of missense variants of uncertain significance in type 1 long QT syndrome.

Bains S, Dotzler SM, Krijger C, Giudicessi JR, ... Wilde AAM, Ackerman MJ
Background
Pathogenic/likely pathogenic (P/LP) variants in the KCNQ1-encoded Kv7.1 potassium channel cause type 1 long QT syndrome (LQT1). Despite the revamped 2015 American College of Medical Genetics (ACMG) variant interpretation guidelines, the burden of KCNQ1 variants of uncertain significance (VUS) in patients with LQTS remains ∼30%.
Objective
The purpose of this study was to determine whether a phenotype-enhanced (PE) variant classification approach could reduce the VUS burden in LQTS genetic testing.
Methods
Retrospective analysis was performed on 79 KCNQ1 missense variants in 356 patients from Mayo Clinic and an independent cohort of 42 variants in 225 patients from Amsterdam University Medical Center (UMC). Each variant was classified initially using the ACMG guidelines and then readjudicated using a PE-ACMG framework that incorporated the LQTS clinical diagnostic Schwartz score plus 4 \"LQT1-defining features\": broad-based/slow upstroke T waves, syncope/seizure during exertion, swimming-associated events, and a maladaptive LQT1 treadmill stress test.
Results
According to the ACMG guidelines, Mayo Clinic variants were classified as follows: 17 of 79 P variants (22%), 34 of 79 LP variants (43%), and 28 of 79 VUS (35%). Similarly, for Amsterdam UMC, the variant distribution was 9 of 42 P variants (22%), 14 of 42 LP variants (33%), and 19 of 42 variants VUS (45%). After PE-ACMG readjudication, the total VUS burden decreased significantly from 28 (35%) to 13 (16%) (P = .0007) for Mayo Clinic and from 19 (45%) to 12 (29%) (P = .02) for Amsterdam UMC.
Conclusion
Phenotype-guided variant adjudication decreased significantly the VUS burden of LQT1 case-derived KCNQ1 missense variants in 2 independent cohorts. This study demonstrates the value of incorporating LQT1-specific phenotype/clinical data to aid in the interpretation of KCNQ1 missense variants identified during genetic testing for LQTS.

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

Heart Rhythm: 27 Feb 2022; 19:435-442
Bains S, Dotzler SM, Krijger C, Giudicessi JR, ... Wilde AAM, Ackerman MJ
Heart Rhythm: 27 Feb 2022; 19:435-442 | PMID: 34798354
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Familial atrial myopathy in a large multigenerational heart-hand syndrome pedigree carrying an LMNA missense variant in rod 2B domain (p.R335W).

Zhang Y, Lin Y, Zhang Y, Wang Y, ... Cui C, Chen M
Background
The literature on laminopathy with ventricular phenotype is extensive. However, the pathogenicity of LMNA variations in atrial lesions still lacks research.
Objective
The purpose of this study was to characterize the atrial phenotypes and possible mechanisms in a large Chinese family with heart-hand syndrome carrying a LMNA missense variant in rod 2B domain (c.1003C>T p.R335W).
Methods
Clinical characteristics were collected on the basis of the pedigree investigation. Comprehensive functional analyses, including molecular dynamic (MD) simulation, cellular, and animal functional assays, determined the pathogenicity in atrial myopathy.
Results
In the pedigree investigation, 6 of 13 of the mutation carriers showed heterogeneous cardiac phenotypes and 8 carriers also had brachydactyly. In silico molecular dynamics simulations predicted increased binding energy of the R335W mutant lamin A. Atrial cardiomyocytes (HL-1, human induced pluripotent stem cell-derived atrial cardiomyocytes) expressing R335W showed abnormal nuclear morphology, compromised DNA repair, and dysfunctional contraction. Adult zebrafish expressing mutant lamin A showed increased P wave duration in the electrocardiogram, decreased peak A wave velocity in echocardiography, and atrial lesions under the transmission electron microscope.
Conclusion
LMNA p.R335W mutation leads to familial heart-hand syndrome characterized by an overlapping phenotype of prominent atrial lesions and brachydactyly. The unstable lamin dimerization and impaired DNA repair are possible mechanisms underlying cardiac phenotypes. Our findings consolidated the genetic role in the course of atrial arrhythmias and cardiac aging, which is helpful in the diagnosis and treatment of cardiac laminopathy.

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

Heart Rhythm: 27 Feb 2022; 19:466-475
Zhang Y, Lin Y, Zhang Y, Wang Y, ... Cui C, Chen M
Heart Rhythm: 27 Feb 2022; 19:466-475 | PMID: 34808346
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Adding six short lines on pulmonary vein isolation circumferences reduces recurrence of paroxysmal atrial fibrillation: Results from a multicenter, single-blind, randomized trial.

Sun J, Chen M, Wang Q, Zhang PP, ... Chen TZ, Li YG
Background
Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) is associated with a non-negligible long-term recurrence rate.
Objectives
The purpose of this study was to investigate whether PVI combined with 6 short ablation lines on the PVI circumferences (PVI+6L group) yields higher success rates than PVI alone (PVI group).
Methods
In this multicenter, single-blind, randomized trial, a total of 390 patients with paroxysmal AF were randomly assigned to the PVI group (n = 193) or the PVI+6L group (n = 197). The primary endpoint was freedom from AF/atrial tachycardia recurrence between 91 and 365 days. Secondary endpoints included AF burden, procedural parameters, and complications.
Results
Freedom from atrial tachyarrhythmia was achieved in 160 of 197 patients (81.2%) in the PVI+6L group and 142 of 193 patients (73.6%) in the PVI group (hazard ratio 0.61; 95% confidence interval 0.39-0.97; P = .040). Mean AF burden tended to be lower in the PVI+6L group compared to the PVI group (1.95% vs 0.53%, P = .097). Procedural and ablation times were slightly longer in the PVI+6L group than in the PVI group (130 ± 25 minutes vs 121 ± 28 minutes; P = .002; and 46 ± 14 minutes vs 41 ± 16 minutes, P = .001, respectively). X-ray exposure was similar (60 ± 54 seconds vs 61 ± 60 seconds; P = .964). Complications occurred in 3 patients (1.6%) in the PVI group and 3 patients (1.5%) in the PVI+6L group.
Conclusion
In patients with paroxysmal AF undergoing catheter ablation, adding 6 short ablation lines on the PVI circumferences could reduce the AF recurrence rate.

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

Heart Rhythm: 27 Feb 2022; 19:344-351
Sun J, Chen M, Wang Q, Zhang PP, ... Chen TZ, Li YG
Heart Rhythm: 27 Feb 2022; 19:344-351 | PMID: 34775069
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Long-term monitoring of arrhythmias with cardiovascular implantable electronic devices in patients with cardiac sarcoidosis.

Bakker A, Mathijssen H, Dorland G, Balt JC, ... Grutters JC, Post MC
Background
Risk stratification for sudden cardiac death (SCD) in cardiac sarcoidosis (CS) is challenging in patients without overt cardiac symptoms.
Objective
The purpose of this study was to determine the incidence of ventricular arrhythmias (VAs) and mortality after long-term monitoring with a cardiovascular implantable electronic device (CIED) in CS patients identified after systematic screening of patients with extracardiac sarcoidosis (ECS).
Methods
A retrospective study was performed in 547 predominantly Caucasian patients with ECS screened for cardiac involvement. If CS was diagnosed, risk stratification (high vs low risk) for SCD was performed by a multidisciplinary team. The primary endpoint was defined as sustained VA, appropriate implantable cardioverter-defibrillator (ICD) therapy, or cardiac death.
Results
In total, 105 patients were included (mean follow-up 33 ± 16 months). An ICD was implanted in 17 high-risk patients (16.2%), whereas 80 low-risk patients (76.1%) received an implantable loop recorder (ILR). Eight low-risk patients (7.6%) did not receive a device. The primary endpoint occurred in 4.8% (n = 5), with an overall annualized event rate of 1.7%. The annualized event rate was 9.8% in high-risk patients and 0.4% in low-risk patients. Nine low-risk patients received an ICD during follow-up, in 7 patients as a result of the ILR recordings. None of these patients required ICD therapy.
Conclusion
In CS patients without overt cardiac symptoms at initial presentation the annualized overall event rate was 1.7%; 10% in high-risk patients, but only 0.4% in low-risk patients. In low-risk patients long-term arrhythmia monitoring with an ILR enabled early detection of clinically important arrhythmias without showing impact on prognosis.

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

Heart Rhythm: 27 Feb 2022; 19:352-360
Bakker A, Mathijssen H, Dorland G, Balt JC, ... Grutters JC, Post MC
Heart Rhythm: 27 Feb 2022; 19:352-360 | PMID: 34843965
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Mechanistic insights into the interaction of cardiac sodium channel Na1.5 with MOG1 and a new molecular mechanism for Brugada syndrome.

Xiong H, Bai X, Quan Z, Yu D, ... Xu C, Wang QK
Background
Mutations in cardiac sodium channel Nav1.5 cause Brugada syndrome (BrS). MOG1 is a chaperone that binds to Nav1.5, facilitates Nav1.5 trafficking to the cell surface, and enhances the amplitude of sodium current INa.
Objective
The purpose of this study was to identify structural elements involved in MOG1-Nav1.5 interaction and their relevance to the pathogenesis of BrS.
Methods
Systematic analyses of large deletions, microdeletions, and point mutations, and glutathione S-transferases pull-down, co-immunoprecipitation, cell surface protein quantification, and patch-clamping of INa were performed.
Results
Large deletion analysis defined the MOG1-Nav1.5 interaction domain to amino acids S476-H585 of Nav1.5 Loop I connecting transmembrane domains I and II. Microdeletion and point mutation analyses further defined the domain to F530T531F532R533R534R535. Mutations F530A, F532A, R533A, and R534A, but not T531A and R535A, significantly reduced MOG1-Nav1.5 interaction and eliminated MOG1-enhanced INa. Mutagenesis analysis identified D24, E36, D44, E53, and E101A of MOG1 as critical residues for interaction with Nav1.5 Loop I. We then characterized 3 mutations at the MOG1-Nav1.5 interaction domain: p.F530V, p.F532C, and p.R535Q reported from patients with long QT syndrome and BrS. We found that p.F532C reduced MOG1-Nav1.5 interaction and eliminated MOG1 function on INa; p.R535Q is also a loss-of-function mutation that reduces INa amplitude in a MOG1-independent manner, whereas p.F530V is benign as it does not have an apparent effect on MOG1 and INa.
Conclusion
Our findings define the MOG1-Nav1.5 interaction domain to a 5-amino-acid motif of F530T531F532R533R534 in Loop I. Mutation p.F532C associated with BrS abolishes Nav1.5 interaction with MOG1 and reduces MOG1-enhanced INa density, thereby uncovering a novel molecular mechanism for the pathogenesis of BrS.

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

Heart Rhythm: 27 Feb 2022; 19:478-489
Xiong H, Bai X, Quan Z, Yu D, ... Xu C, Wang QK
Heart Rhythm: 27 Feb 2022; 19:478-489 | PMID: 34843967
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

An overview of heart rhythm disorders and management in myotonic dystrophy type 1.

Gossios TD, Providencia R, Creta A, Segal OR, ... Wahbi K, Savvatis K
Myotonic dystrophy type 1 (DM1) is the most common adult form of muscular dystrophy, presenting with a constellation of systemic findings secondary to a CTG triplet expansion of the noncoding region of the DMPK gene. Cardiac involvement is frequent, with conduction disease and supraventricular and ventricular arrhythmias being the most prevalent cardiac manifestations, often developing from a young age. The development of cardiac arrhythmias has been linked to increased morbidity and mortality, with sudden cardiac death well described. Strategies to mitigate risk of arrhythmic death have been developed. In this review, we outline the current knowledge on the pathophysiology of rhythm abnormalities in patients with myotonic dystrophy and summarize available knowledge on arrhythmic risk stratification. We also review management strategies from an electrophysiological perspective, attempting to underline the substantial unmet need to address residual arrhythmic risks for this population.

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

Heart Rhythm: 27 Feb 2022; 19:497-504
Gossios TD, Providencia R, Creta A, Segal OR, ... Wahbi K, Savvatis K
Heart Rhythm: 27 Feb 2022; 19:497-504 | PMID: 34843968
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Risk factors for atrioventricular block after occlusion for perimembranous ventricular septal defect.

Lin L, Liu J, Guo X, Chen H, ... Chen L, Chen Z
Background
The risk factors for complete atrioventricular block (CAVB) after device closure of perimembranous ventricular septal defect (pmVSD) remain unclear.
Objective
The purpose of this study was to analyze the incidence and risk factors for CAVB after device closure for pmVSD.
Methods
We reviewed 1884 patients with pmVSD who had undergone successful device occlusion between June 2005 and January 2020. Permanent CAVB was defined as CAVB requiring implantation of a permanent pacemaker (PPM) or extraction of the occluder.
Results
In total, 14 patients (0.7%) developed permanent CAVB. Of these patients, 10 (0.5%) required PPM implantation. Four permanent CAVB occurred within 7 days after the procedure (acute), 2 between 7 and 30 days (subacute), 3 between 30 days and 1 year (late), and 5 more than 1 year (very late). None of the subacute, late, and very late CAVB recovered normal conduction with medication and eventually required device removal or PPM implantation. Four patients with acute CAVB and 1 with subacute CAVB underwent device removal, and 4 (80%) recovered normal conduction. Multivariate regression revealed that the ratio of device to defect size was the only independent risk factor for permanent CAVB (odds ratio 3.027; 95% confidence interval 1.476-6.209; P = .003).
Conclusion
The incidences of permanent CAVB after occlusion for pmVSD and PPM implantation were 0.7% and 0.5%, respectively. The ratio of device to defect size was the only independent risk factor for permanent CAVB. Device removal is an effective therapeutic modality for recovering normal conduction in acute and subacute CAVB patients.

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

Heart Rhythm: 27 Feb 2022; 19:389-396
Lin L, Liu J, Guo X, Chen H, ... Chen L, Chen Z
Heart Rhythm: 27 Feb 2022; 19:389-396 | PMID: 34843969
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Sotalol versus amiodarone for postoperative junctional tachycardia after congenital heart surgery.

Rochelson E, Valdés SO, Asadourian V, Patel R, ... Miyake CY, Kim JJ
Background
Junctional ectopic tachycardia (JET) is a common arrhythmia after congenital heart disease surgery. There is variability in the choice of antiarrhythmic therapy, with amiodarone used commonly. Intravenous (IV) sotalol is a newly available agent that may be useful for JET.
Objective
The purpose of this study was to evaluate the safety and efficacy of IV sotalol for postoperative JET and compare outcomes with IV amiodarone.
Methods
This is a retrospective single-center study of all patients who received IV sotalol or IV amiodarone for postoperative JET at Texas Children\'s Hospital from December 15, 2015, to December 15, 2020. Data included antiarrhythmic efficacy, hemodynamics, and adverse effects. Successful JET control was defined as a decrease in JET rate to <170 beats/min (or decrease by >20%), or conversion to sinus rhythm, with persistent control over 24 hours without requiring alternative antiarrhythmics or mechanical support.
Results
A total of 32 patients (median age 71 days; interquartile range 17-221 days) received IV amiodarone (n = 20 [62%]) or IV sotalol (n = 12 [38%]) for postoperative JET. Amiodarone was successful in treating JET in 75% of cases; sotalol was successful in 83%. The JET rate decreased faster over the first 90 minutes after a sotalol bolus (25 beats/min per hour) than after an amiodarone bolus (8 beats/min per hour) (P < .01); no heart rate difference was seen after 24 hours. Amiodarone infusion was discontinued early because of hypotension/bradycardia in 2 patients; this was not required in any patients receiving sotalol.
Conclusion
For children with postoperative JET, both IV sotalol and amiodarone are safe and efficacious. IV sotalol may lead to a faster improvement in heart rate.

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

Heart Rhythm: 27 Feb 2022; 19:450-456
Rochelson E, Valdés SO, Asadourian V, Patel R, ... Miyake CY, Kim JJ
Heart Rhythm: 27 Feb 2022; 19:450-456 | PMID: 34801734
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Bradyarrhythmias detected by extended rhythm recording in patients undergoing transcatheter aortic valve replacement (Brady-TAVR Study).

Tarakji KG, Patel D, Krishnaswamy A, Hussein A, ... Wazni OM, Kapadia SR
Background
Bradyarrhythmias leading to permanent pacemaker (PPM) implantation continue to be a complication after transcatheter aortic valve replacement (TAVR).
Objective
The purpose of this study was to assess the prevalence of bradyarrhythmias using an electrocardiographic (ECG) extended rhythm recording in patients pre- and post-TAVR and whether they can predict the need for PPM.
Methods
This was a prospective single-center study in patients undergoing TAVR. Patients received an ECG patch for 2 weeks pre-, immediately post-, and 2-3 months post-TAVR. Caring physicians were blinded to the results of the patch except when predefined urgent arrhythmias were detected. The main outcome was the need for PPM implantation after TAVR.
Results
We enrolled 110 patients, of whom 96 underwent TAVR and were included in the final analysis. Bradyarrhythmias, defined as a pause of 3 seconds or more, occurred in 5.2%, 12.7%, and 7% of patients pre-, immediately post-, and 2-3 months post-TAVR, respectively. PPM implantation occurred in 12 patients (12.5%), of whom 9 (9.4%) underwent implantation during their index hospitalization while 3 (3.1%) required implantation postdischarge for indications other than heart block. No patients required PPM after receiving an ECG patch 2-3 months post-TAVR. Significant baseline predictors for the need for PPM included the presence of right bundle branch block and increased QRS duration. Bradyarrhythmias detected by the ECG patch did not predict the need for PPM at either the index hospitalization or the follow-up period.
Conclusion
Bradyarrhythmias are common and can be detected with extended ECG monitoring before and after TAVR; however, in our study they did not predict the need for PPM after TAVR (ClinicalTrials.gov identifier: NCT03180073).

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

Heart Rhythm: 27 Feb 2022; 19:381-388
Tarakji KG, Patel D, Krishnaswamy A, Hussein A, ... Wazni OM, Kapadia SR
Heart Rhythm: 27 Feb 2022; 19:381-388 | PMID: 34801735
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Clinical performance of implantable cardioverter-defibrillator lead monitoring diagnostics.

Poole JE, Swerdlow CD, Tarakji KG, Mittal S, ... Gunderson B, Wilkoff BL
Background
Implantable cardioverter-defibrillator (ICD) lead monitoring diagnostic alerts facilitate the diagnosis of structural lead failure.
Objective
The purpose of this study was to prospectively study the performance of Medtronic ICD lead monitoring alerts.
Methods
A prespecified ancillary substudy, World-Wide Randomized Antibiotic Envelope Infection Prevention Trial, was conducted in patients with an ICD with all available alerts enabled. The investigators reported possible lead system events (LSEs), with or without an alert. An independent committee reviewed all data and classified events as lead failure, other LSE, or nonlead system events (NLEs).
Results
In 4942 patients who were followed for 19.4 ± 8.7 months, there were 124 alerts (65 LSEs, 59 NLEs) and 19 LSEs without an alert. Lead monitoring alerts had 100% sensitivity for the 48 adjudicated lead failures (95% confidence interval 92.6%-100%) and for 10 events adjudicated as either lead failure or connection issue. The positive predictive value of alerts for lead failure was 38.7% (48 of 124). For 34 pace-sense lead failures, an alert that incorporated oversensing was more sensitive than the pacing impedance threshold alert (33 patients [97.1%] vs 9 patients [26.5%]; P < .0001). However, the sensitivity was only 13.6% for lead dislodgments or perforations. Inappropriate shocks occurred in 2 patients with pace-sense lead failure (5.9%). No patient had unnecessary lead replacement for any of the NLEs.
Conclusion
In this first real-world prospective study, lead monitoring alerts had 100% sensitivity for identifying lead failures. Although their positive predictive value was modest, no false-positive alerts resulted in an unnecessary lead replacement. For the diagnosis of pace-sense lead failure, an alert for oversensing was more sensitive than a pacing impedance threshold alert.
Trial registration
ClinicalTrials.gov identifier: NCT02277990.

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

Heart Rhythm: 27 Feb 2022; 19:363-371
Poole JE, Swerdlow CD, Tarakji KG, Mittal S, ... Gunderson B, Wilkoff BL
Heart Rhythm: 27 Feb 2022; 19:363-371 | PMID: 34767985
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Magnetic field-induced interactions between phones containing magnets and cardiovascular implantable electronic devices: Flip it to be safe?

Lacour P, Dang PL, Heinzel FR, Parwani AS, ... Pieske B, Blaschke F
Background
Recent case reports and small studies have reported activation of the magnet-sensitive switches in cardiovascular implantable electronic devices (CIEDs) by the new iPhone 12 series, initiating asynchronous pacing in pacemakers and suspension of antitachycardia therapies in implantable cardioverter-defibrillators (ICDs).
Objective
The purpose of this prospective single-center observational study was to quantify the risk of magnetic field interactions of the iPhone 12 with CIEDs.
Methods
A representative model of each CIED series from all manufacturers was tested ex vivo. Incidence and minimum distance necessary for magnet mode triggering were analyzed in 164 CIED patients with either the front or the back of the phone facing the device. The magnetic field of the iPhone 12 was analyzed using a 3-axis Hall probe.
Results
Ex vivo, magnetic interference occurred in 84.6% with the back compared to 46.2% with the front of the iPhone 12 facing the CIED. In vivo, activation of the magnet-sensitive switch occurred in 30 CIED patients (18.3%; 21 pacemaker, 9 ICD) when the iPhone 12 was placed in close proximity over the CIED pocket and the back of the phone was facing the skin. Multiple binary logistic regression analysis identified implantation depth (95% confidence interval 0.02-0.24) as an independent predictor of magnet-sensitive switch activation.
Conclusion
Magnetic field interactions occur only in close proximity and with precise alignment of the iPhone 12 and CIEDs. It is important to advise CIED patients to not put the iPhone 12 directly on the skin above the CIED. Further recommendations are not necessary.

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

Heart Rhythm: 27 Feb 2022; 19:372-380
Lacour P, Dang PL, Heinzel FR, Parwani AS, ... Pieske B, Blaschke F
Heart Rhythm: 27 Feb 2022; 19:372-380 | PMID: 34767986
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Pediatric T-wave memory after accessory pathway ablation in Wolff-Parkinson-White syndrome.

Austin KM, Alexander ME, Triedman JK
Background
Altered ventricular depolarization due to manifest accessory pathway conduction (ie, Wolff-Parkinson-White syndrome) leads to repolarization abnormalities that persist after pathway ablation. The term T-wave memory (TWM) has been applied to these changes, as the postablation T-wave vector \"remembers\" the pre-excited QRS vector. In adults, these abnormalities can be misinterpreted as ischemia leading to unnecessary interventions. To date, no comprehensive studies have evaluated this phenomenon in the pediatric population.
Objective
The purpose of this study was to define TWM in the pediatric population, identify preablation risk factors, and delineate the timeline of recovery.
Methods
Pre- and postablation electrocardiograms (ECGs) in patients ≤25 years were analyzed over a 5-year period. Frontal plane QTc interval, T-wave axis, QRST angle, and T-wave inversions were used to identify patients with TWM. Univariate analysis was performed to determine the association of preablation ECG features with the outcome of TWM.
Results
TWM was present in 42% of pediatric patients, with resolution occurring within 3 months of ablation. Preablation QRS axis <0° was a strong predictor of TWM (odds ratio [OR] 15.2; 95% confidence interval [CI] 5.7-40), followed by posteroseptal pathway location (right posteroseptal-OR 8.9; 95% CI 4.2-18.8; left posteroseptal-OR 6.1; 95% CI 1.7-22.3). The degree of pre-excitation had a modest association with the development of TWM. No adverse events were observed.
Conclusion
TWM is less common in children compared to adults, and normalization occurred within 3 months postablation. The most predictive features for the development of TWM include a leftward pre-excited QRS axis and posteroseptal pathway location.

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

Heart Rhythm: 27 Feb 2022; 19:459-465
Austin KM, Alexander ME, Triedman JK
Heart Rhythm: 27 Feb 2022; 19:459-465 | PMID: 34767987
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Sex-specific aspects of phospholamban cardiomyopathy: The importance and prognostic value of low-voltage electrocardiograms.

de Brouwer R, Meems LMG, Verstraelen TE, Mahmoud B, ... van den Berg MP, de Boer RA
Background
A pathogenic variant in the gene encoding phospholamban (PLN), a protein that regulates calcium homeostasis of cardiomyocytes, causes PLN cardiomyopathy. It is characterized by a high arrhythmic burden and can progress to severe cardiomyopathy. Risk assessment guides implantable cardioverter-defibrillator therapy and benefits from personalization. Whether sex-specific differences in PLN cardiomyopathy exist is unknown.
Objective
The purpose of this study was to improve the accuracy of PLN cardiomyopathy diagnosis and risk assessment by investigating sex-specific aspects.
Methods
We analyzed a multicenter cohort of 933 patients (412 male, 521 female) with the PLN p.(Arg14del) pathogenic variant following up on a recently developed PLN risk model. Sex-specific differences in the incidence of risk model components were investigated: low-voltage electrocardiogram (ECG), premature ventricular contractions, negative T waves, and left ventricular ejection fraction.
Results
Sustained ventricular arrhythmias (VAs) occurred in 77 males (18.7%) and 61 females (11.7%) (P = .004). Of the 933 cohort members, 287 (31%) had ≥1 low-voltage ECG during follow-up (180 females [63%], 107 males [37%]; P = .006). Female sex, age, age at clinical presentation, and proband status predicted low-voltage ECG during follow-up (area under the curve: 0.78). Sustained VA-free survival was lowest in males with low-voltage ECG (P <.001).
Conclusion
Low-voltage ECGs predict sustained VA and are a component of the PLN risk model. Low-voltage ECGs are more common in females, yet prognostic value is greater in males. Future studies should determine the impact of this difference on the risk prediction of PLN cardiomyopathy and possibly other cardiomyopathies.

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

Heart Rhythm: 27 Feb 2022; 19:427-434
de Brouwer R, Meems LMG, Verstraelen TE, Mahmoud B, ... van den Berg MP, de Boer RA
Heart Rhythm: 27 Feb 2022; 19:427-434 | PMID: 34767988
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Safety and outcome of nurse-led syncope clinics and implantable loop recorder implants.

Eftekhari H, He H, Lee JD, Paul G, ... Hayat S, Osman F
Background
Implantable loop recorders (ILRs) are effective in achieving symptom-rhythm correlation. Data on the diagnostic yield of ILRs, on nurse-led syncope clinics, and on nurse-led ILR implants are limited.
Objective
We evaluated the safety and efficacy of our nurse-led syncope clinic and nurse-led ILR implants.
Methods
A retrospective study of all consecutive patients undergoing nurse-led ILR implantations was performed between April 2016 and April 2018. Patients were referred from both nurse-led and physician-led clinics. Data were collected on baseline demographic characteristics, referral source, symptom-rhythm correlation, ILR findings, and subsequent changes to management. All ILRs were enrolled into remote monitoring with automatic arrhythmia detection, and all immediate (≤24 hours) ILR implant complications were recorded. Comparisons were made between nurse-led and physician-led clinics and subsequent outcomes.
Results
A total of 432 patients with an ILR were identified: 164 (38%) from nurse-led and 268 (62%) from physician-led clinics; 200 (46%) were women (mean age 66.5 ± 18.2 years; mean follow-up duration 28.9 ± 9.5 months). Primary ILR indications were syncope (n = 251 [58%]), presyncope (n = 33 [7%]), palpitation (n = 39 [9%]), cryptogenic stroke (n = 78 [18%]), and other reasons (n = 31 [7%]). No immediate ILR implant complications occurred. Overall, 156 patients (36%) had a change in management as a direct result of ILR findings, with no overall differences between nurse-led and physician-led clinics (35% vs 36%; P = .7). More patients had newly diagnosed atrial fibrillation in physician-led clinics (15% vs 7%; P = .01), and more patients had pacemaker implants for bradycardia in nurse-led clinics (23% vs 13%; P < .01).
Conclusion
Nurse-led ILR implantation was safe and effective. Nurse-led syncope clinics achieved good symptom-rhythm correlation with resultant significant changes to management in comparison to physician-led clinics. Larger prospective studies are needed to evaluate their longer-term impact.

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

Heart Rhythm: 27 Feb 2022; 19:443-447
Eftekhari H, He H, Lee JD, Paul G, ... Hayat S, Osman F
Heart Rhythm: 27 Feb 2022; 19:443-447 | PMID: 34767989
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Reduced Motion External Defibrillation (RMD): Reduced Subject Motion with Equivalent Defibrillation Efficiency validated in Swine.

Schmidt EJ, Elahi H, Meyer ES, Baumgaertner R, ... Oberdier MT, Halperin HR
Background
External defibrillators are used for arrhythmia cardioversion and for defibrillating during cardiac arrest. During defibrillation, short-duration Biphasic pulses cause intense motion due to rapid chest-wall muscle contraction. A reduced-motion external defibrillator (RMD) was constructed by integrating a commercial defibrillator with a Tetanizing-waveform generator. A long-duration low-amplitude Tetanizing-waveform slowly stimulated the chest musculature prior to the Biphasic pulse, reducing muscle contraction during the shock.
Objective
Evaluate RMD defibrillation in swine for subject-motion during defibrillation pulses and for defibrillation effectiveness. RMD defibrillation can reduce the duration of arrhythmia ablation-therapy or simplify cardioversion procedures.
Methods
The Tetanizing unit delivered a triangular 1-kHz pulse of 0.25-2.0sec duration and 10-100Volt peak amplitude, subsequently triggering the conventional defibrillator to output standard 1-200J energy Biphasic pulses at the next R-wave. Forward-limb motion was evaluated by measuring Peak Acceleration and Limb Work during RMD (Tetanizing+Biphasic) or Biphasic-pulse-only waveforms at 10-3sec sampling-rate. Seven swine were arrested electrically and subsequently defibrillated. Biphasic-pulse-only and RMD defibrillations were repeated 25-35 times/swine, varying Tetanizing parameters and the Biphasic-pulse energy. Defibrillation thresholds (DFTs) were established by measuring the minimum energy required to restore sinus-rhythm with Biphasic-pulse-only or RMD defibrillations.
Results
Two forward-limb acceleration-peaks occurred during both the Tetanizing-waveform and Biphasic-pulse, indicating rapid and slower nociceptic (pain-sensation) nerve-fiber activation. Optimal RMD Tetanizing-parameters (25-35V, 0.25-0.75sec duration), relative to Biphasic-pulse-only defibrillations, resulted in 74+10% smaller Peak Accelerations and 85+10% reduced Limb Work. DFT energies were identical, comparing RMD to Biphasic-pulse-only defibrillations.
Conclusion
Relative to conventional defibrillations, RMD defibrillations maintain rhythm-restoration efficiency with drastically reduced subject-motion.

Copyright © 2022. Published by Elsevier Inc.

Heart Rhythm: 27 Feb 2022; epub ahead of print
Schmidt EJ, Elahi H, Meyer ES, Baumgaertner R, ... Oberdier MT, Halperin HR
Heart Rhythm: 27 Feb 2022; epub ahead of print | PMID: 35240311
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Mechanism of the effects of sodium channel blockade on the arrhythmogenic substrate of Brugada syndrome.

Nademanee K, Veerakul G, Nogami A, Lou Q, ... Boukens BJ, Haissaguerre M
Background
The mechanisms by which sodium channel blockade and high-rate pacing modify electrogram (EGM) substrates of Brugada syndrome (BrS) have not been elucidated.
Objective
The purpose of this study was to determine the effect of ajmaline and high pacing rate on the BrS substrates.
Methods
Thirty-two patients with BrS (mean age 40 ± 12 years) and frequent ventricular fibrillation episodes underwent right ventricular outflow tract substrate electroanatomical and electrocardiographic imaging (ECGI) mapping before and after ajmaline administration and during high-rate atrial pacing. In 4 patients, epicardial mapping was performed using open thoracotomy with targeted biopsies.
Results
Ajmaline increased the activation time delay in the substrate (33%; P = .002), ST-segment elevation in the right precordial leads (74%; P < .0001), and the area of delayed activation (170%; P < .0001), coinciding with the increased substrate size (75%; P < .0001). High atrial pacing rate increased the abnormal EGM duration at the right ventricular outflow tract areas from 112 ± 48 to 143 ± 66 ms (P = .003) and produced intermittent conduction block and/or excitation failure at the substrate sites, especially after ajmaline administration. Biopsies from the 4 patients with thoracotomy showed epicardial fibrosis where EGMs were normal at baseline but became fractionated after ajmaline administration. In some areas, local activation was absent and unipolar EGMs had a monophasic morphology resembling the shape of the action potential.
Conclusion
Sodium current reduction with ajmaline severely compromises impulse conduction at the BrS fibrotic substrates by producing fractionated EGMs, conduction block, or excitation failure, leading to the Brugada ECG pattern and favoring ventricular fibrillation genesis.

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

Heart Rhythm: 27 Feb 2022; 19:407-416
Nademanee K, Veerakul G, Nogami A, Lou Q, ... Boukens BJ, Haissaguerre M
Heart Rhythm: 27 Feb 2022; 19:407-416 | PMID: 34742919
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

High-density epicardial mapping in Brugada syndrome: Depolarization and repolarization abnormalities.

Pannone L, Monaco C, Sorgente A, Vergara P, ... Chierchia GB, de Asmundis C
Background
The pathogenesis of Brugada syndrome (BrS) and consequently of abnormal electrograms (aEGMs) found in the epicardium of the right ventricular outflow tract (RVOT-EPI) is controversial.
Objective
The purpose of this study was to analyze aEGM from high-density RVOT-EPI electroanatomic mapping (EAM).
Methods
All patients undergoing RVOT-EPI EAM with the HD-Grid catheter for BrS were retrospectively included. Maps were acquired before and after ajmaline, and all patients had concomitant noninvasive electrocardiographic imaging with annotation of RVOT-EPI latest activation time (RVOTat). High-frequency potentials (HFPs) were defined as ventricular potentials occurring during or after the far-field ventricular EGM showing a local activation time (HFPat). Low-frequency potentials (LFPs) were defined as aEGMs occurring after near-field ventricular activation showing fractionation or delayed components. Their activation time from surface ECG was defined as LFPat.
Results
Fifteen consecutive patients were included in the study. At EAM before ajmaline, 7 patients (46.7%) showed LFPs. All patients showed HFPs before and after ajmaline and LFPs after ajmaline. Mean HFPat (134.4 vs 65.3 ms, P <.001), mean LFPat (224.6 vs 113.6 ms, P <.001), and mean RVOTat (124.8 vs 55.9 ms, P <.001) increased after ajmaline. RVOTat correlated with HFPat before (ρ = 0.76) and after ajmaline (ρ = 0.82), while RVOTat was shorter than LFPat before (P <.001) and after ajmaline (P <.001). BrS patients with history of aborted sudden cardiac death had longer aEGMs after ajmaline.
Conclusion
Two different types of aEGMs are described from BrS high-density epicardial mapping. This might correlate with depolarization and repolarization abnormalities.

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

Heart Rhythm: 27 Feb 2022; 19:397-404
Pannone L, Monaco C, Sorgente A, Vergara P, ... Chierchia GB, de Asmundis C
Heart Rhythm: 27 Feb 2022; 19:397-404 | PMID: 34601129
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

Multisite conduction block in the epicardial substrate of Brugada syndrome.

Haïssaguerre M, Nademanee K, Sacher F, Cheniti G, ... Vigmond E, Bernus O
Background
The Brugada pattern manifests as a spontaneous variability of the electrocardiographic marker, suggesting a variability of the underlying electrical substrate.
Objective
The purpose of this study was to investigate the response of the epicardial substrate of Brugada syndrome (BrS) to programmed ventricular stimulation and to Na blocker infusion.
Methods
We investigated 6 patients (all male; mean age 54 ± 14 years) with BrS and recurrent ventricular fibrillation. Five had no type 1 BrS electrocardiogram pattern at admission. They underwent combined epicardial-endocardial mapping using multielectrode catheters. Changes in epicardial electrograms were evaluated during single endocardial extrastimulation and after low-dose ajmaline infusion (0.5 mg/kg in 5 minutes).
Results
All patients had a region in the anterior epicardial right ventricle with prolonged multicomponent electrograms. Single extrastimulation prolonged late epicardial components by 59 ± 31 ms and in 4 patients abolished epicardial components at some sites, without reactivation by surrounding activated sites. These localized blocks occurred at an initial coupling interval of 335 ± 58 ms and then expanded to other sites, being observed in up to 40% of epicardial sites. Ajmaline infusion prolonged electrogram duration in all and produced localized blocks in 62% of sites in the same patients as during extrastimulation. Epicardial conduction recovery after ajmaline occurred intermittently and at discontinuous sites and produced beat-to-beat changes in local repolarization, resulting in an area of marked electrical disparity. These changes were consistent with models based on microstructural alterations under critical propagation conditions.
Conclusion
In BrS, localized functional conduction blocks occur at multiple epicardial sites and with variable patterns, without being reactivated from the surrounding sites.

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

Heart Rhythm: 27 Feb 2022; 19:417-426
Haïssaguerre M, Nademanee K, Sacher F, Cheniti G, ... Vigmond E, Bernus O
Heart Rhythm: 27 Feb 2022; 19:417-426 | PMID: 34737095
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:
Abstract

How to perform extrathoracic venous access for cardiac implantable electronic device placement: Detailed description of techniques.

Su J, Kusumoto FM, Zhou X, Elayi CS
Venous access is needed for implantation of cardiac implantable electronic devices (CIEDs) with endocardial leads. Extrathoracic venous access in the prepectoral region has become the standard of care for CIED implantation because of lower risks for pneumothorax and likely less lead malfunction due to subclavian crush syndrome. The most common extrathoracic venous access sites in the pectoral region are extrathoracic subclavian vein access, axillary vein access, and cephalic vein access. This review provides a detailed description of the anatomy, technical considerations, and relative advantages and disadvantages of each of these extrathoracic venous access sites.

Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart Rhythm: 26 Feb 2022; epub ahead of print
Su J, Kusumoto FM, Zhou X, Elayi CS
Heart Rhythm: 26 Feb 2022; epub ahead of print | PMID: 35231611
Go to: DOI | PubMed | PDF | Google Scholar |
Impact:

This program is still in alpha version.