Cryofreezing for slow-pathway modification in patients with slow-fast AVNRT: Efficacy, safety, and electroanatomical relation between sites of transient AV block and sites of successful cryoablation.

Fukuda R, Nakahara S, Wakamatsu Y, Hori Y, ... Ishikawa T, Taguchi I
Introduction
Cryoablation has emerged as an alternative to radiofrequency ablation for treating atrioventricular nodal reentrant tachycardia (AVNRT). The aim of this prospective study was to evaluate the efficacy and safety of cryoapplication at sites within the mid/high septal region of Koch\'s triangle and the relation between sites of transient AV block (AVB) and sites of successful cryoablation.
Methods and results
Included were 45 consecutive patients undergoing slow-fast AVNRT cryoablation. Initial delivery of cryoenergy was to the mid-septal to high septal region of Koch\'s triangle. Transient AVB occurred during cryoenergy delivery in 62% (28/45) of patients. Median distance between sites at which cryofreezing successfully eliminated slow pathway conduction and sites of AVB was 4.0 (3.25-5.0) mm. Sites of successful cryoablation tended to be to the left and inferior to the AVB sites. The atrial/ventricular electrogram ratio was significantly lower at sites of successful cryoablation than at AVB sites (0.25 [0.17-0.56] vs. 0.80 [0.36-1.25], p < .001). Delayed discrete or fractionated atrial electrograms were recorded more frequently at sites of successful cryoablation than at AVB sites (78% vs. 20%, p < .001). No persistent AV conduction disturbance occurred, and 96% (43/45) of patients showed absence of recurrence at a median follow-up time of 25.0 months.
Conclusion
Cryoablation of slow-fast AVNRT and targeting the mid/high septal region of Koch\'s triangle was highly successful. AVB frequently emerged near the site at which the slow pathway was eliminated but always resolved by regulating the energy delivery under careful monitoring, and it may be distinguishable by its local electrogram features.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3135-3142

Atrial fibrillation incidence, prevalence, predictors and adverse outcomes in acute coronary syndromes: a pooled analysis of data from 8 million patients.

Noubiap JJ, Agbaedeng TA, Nyaga UF, Lau DH, ... Nicholls SJ, Sanders P
Objective
To summarize data on the prevalence/incidence, risk factors and prognosis of atrial fibrillation (AF) in patients with acute coronary syndromes (ACS).
Methods
MEDLINE, Embase, and Web of Science were searched to identify all published studies providing relevant data through August 23, 2020. Random-effects meta-analysis method was used to pool estimates.
Results
We included 109 studies reporting data from a pooled population of 8,239,364 patients. The prevalence rates were 5.8% for pre-existing AF, 7.3% for newly diagnosed AF, and 11.3% for prevalent (total) AF, in patients with ACS. Predictors of newly diagnosed AF included age (per year increase) (adjusted odds ratio [aOR] 1.05), C-reactive protein (aOR 1.49), left atrial (LA) diameter (aOR 1.08), LA dilatation (aOR 2.32), left ventricular ejection fraction <40% (aOR 1.82), hypertension (aOR 1.87), and Killip ˃1 (aOR 1.85), p<0.01 in all analyses. Newly diagnosed AF was associated with an increased risk of acute heart failure (aHR 3.20), acute kidney injury (aHR 3.09), re-infarction (aHR 1.96), stroke (aHR 2.15), major bleeding (aHR 2.93), and mortality (aHR 1.80) in the short term; and with an increased risk of heart failure (aHR 2.21), stroke (aHR 1.75), mortality (aHR 1.67), CV mortality (aHR 2.09), sudden cardiac death (aHR 1.53), and a composite of major adverse cardiovascular events (aHR 1.54) in the long term (beyond 1 month), p<0.05 in all analyses.
Conclusion
One in nine patients with ACS has AF, with a high proportion of newly diagnosed AF. Atrial fibrillation, in particular newly diagnosed AF, is associated with poor short-term and long-term outcomes in patients with ACS. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 03 Jan 2022; epub ahead of print

Epicardial atrial pacing after the extracardiac Fontan operation: Feasibility of an entirely transvenous approach.

Hoyt WJ, Moore JP, Shannon KM, Kannankeril PJ, Fish FA
This series describes an innovative technique for pacing in patients with sinus node dysfunction after extracardiac Fontan surgery. This transpulmonary approach to the left atrial epi-myocardium has been successfully applied to three patients at two centers and resulted in excellent acute and midterm pacing characteristics without known complications. The principal advantage of this procedure in comparison to prior iterations is the absence of pacing material within the pulmonary venous atrium, so that future systemic thromboembolism risk is minimized. The transpulmonary approach for permanent atrial pacing offers a novel solution to the unique challenges for patients after extracardiac Fontan operation.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:128-133

Hourly variability in outflow tract ectopy as a predictor of its site of origin.

Waight MC, Li AC, Leung LW, Wiles BM, ... Restrepo AJ, Saba MM
Introduction
Before ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO.
Methods
Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-h ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left-sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation.
Results
High VE variability (coefficient of variation ≥0.7) and the presence of any hour with <50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%).
Conclusion
VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favorably to existing ECG algorithms.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:7-16

Persistent left superior vena cava transvenous lead extraction: A European experience.

Akhtar Z, Sohal M, Starck CT, Mazzone P, ... Zaidi A, Gallagher MM
Background
Transvenous lead extraction (TLE) is rising in parallel to cardiac implantable electronic device implantations. Persistent left side superior vena cava (PLSVC) is a relatively common anatomical variant in the healthy population; TLE in patients with a PLSVC is rare.
Method
Data were collated from 6 European TLE institutes of 10 patients who had undergone lead extraction with a PLSVC. Patient demographics, procedural challenges and outcomes were reported.
Results
Ten patients aged 73.4 ± 7.8 years (60% male) underwent TLE of 20 leads (3 left ventricle, 10 right ventricle, 7 right atrium) with dwell time of 82.95 ± 39.1 months. Of the 10 cases, 4 had an infection indication and 5 were biventricular system extractions; 25% of the extracted leads were defibrillator leads. The majority of the procedures were completed in the cardiac catheterization suite (80%) under general anaesthesia (60%) by cardiologists (80%) using a rotational powered sheath (65%). The Tandem approach was used successfully in 3 cases. Complete procedural success was obtained in 100% of cases in the absence of complications within 127.4 ± 74.7 min. There was no 30-day mortality.
Conclusion
TLE in PLSVC is feasible albeit rare. Standard extraction techniques in experienced hands are associated with favorable outcomes; the Tandem procedure may be an additional technique to improve the safety and efficacy of TLE in PLSVC.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:102-108

An active fixation quadripolar left ventricular lead for cardiac resynchronisation therapy with reduced post-operative complication rates.

Robertson C, Duffey O, Tang PT, Fairhurst N, ... Betts TR, Herring N
Background
The rate of left ventricular (LV) lead displacement after cardiac resynchronization therapy (CRT) remains high despite improvements in lead technology. In 2017, a novel quadripolar lead with active fixation technology became available in the UK.
Methods
This was a retrospective, observational study analysing device complications in 476 consecutive patients undergoing successful first-time implantation of a CRT device at a tertiary centre from 2017 to 2020.
Results
Both active (n=135) and passive fixation (n=341) quadripolar leads had similar success rates for implantation (99.3% vs 98.8%, p=1.00), although the pacing threshold (0.89 [0.60-1.25] vs 1.00 [0.70-1.60] V, p=0.01) and lead impedance (632 [552-794] vs 730 [636-862] Ohms, p<0.0001) were significantly lower for the active fixation lead. Patients receiving an active fixation lead had a reduced incidence of lead displacement at 6 months (0.74% vs 4.69%, p=0.036). There was no significant difference in the rate of right atrial (RA) and right ventricular (RV) lead displacement between the two groups (RA: 1.48% vs 1.17%, p=0.68; RV: 2.22% vs 1.76%, p=0.72). Reprogramming the LV lead after displacement was unsuccessful in most cases (successful reprogramming: Active fix = 0/1, Passive fix = 1/16) therefore nearly all patients required a repeat procedure. As a result, the rate of intervention within 6 months for lead displacement was significantly lower when patients were implanted with the active fixation lead (0.74% vs 4.40%, p=0.049).
Conclusion
The novel active fixation lead in our study has a lower incidence of lead displacement and re-intervention compared to conventional quadripolar leads for CRT. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 29 Dec 2021; epub ahead of print

Trends in hospitalization and factors associated with in-hospital death among pediatric admissions with implantable cardioverter defibrillators.

Qasim A, Dam T, Kim JJ, Valdes SO, ... Morris SA, Miyake CY
Background
As pediatric implantable cardioverter defibrillator (ICD) utilization increases, hospital admission rates will increase. Data regarding hospitalizations among pediatric patients with ICDs are lacking. In addition, hospital mortality rates are unknown. This study aimed to evaluate 1) trends in hospitalization rates from 2000 to 2016, 2) hospital mortality, and 3) factors associated with hospital mortality among pediatric admissions with ICDs.
Methods
The Kids\' Inpatient Database (2000,2003,2006,2009,2012,2016) was used to identify all hospitalizations with an existing ICD ≤20 years of age. ICD9/10 codes were used to stratify admissions by underlying diagnostic category as: 1) congenital heart disease (CHD), 2) primary arrhythmia, 3) primary cardiomyopathy, or 4) other. Trends were analyzed using linear regression. Hospital and patient characteristics among hospital deaths were compared to those surviving to discharge using mixed multivariable logistic regression, accounting for hospital clustering.
Results
Of 42,570,716 hospitalizations, 4165 were admitted <21 years with an ICD. ICD hospitalizations increased four-fold (p = 0.002) between 2000-2016. Hospital death occurred in 54 (1.3%). In multivariable analysis, cardiomyopathy (OR 3.5, 95%CI 1.1-11.2, p=0.04) and CHD (OR 4.8, 95%CI 1.5-15.6, p=0.01) were significantly associated with mortality. In further exploratory multivariable analysis incorporating a coexisting diagnosis of heart failure, only the presence of heart failure remained associated with mortality (OR 8.6, 95%CI 3.7-20.0, p<0.0001).
Conclusions
Pediatric ICD hospitalization are increasing over time and hospital mortality is low (1.3%). Hospital mortality is associated with cardiomyopathy or CHD; however, the underlying driver for in-hospital death may be heart failure. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 29 Dec 2021; epub ahead of print

Differentiating Left Bundle Branch Pacing and Left Ventricular Septal Pacing: An Algorithm Based on Intracardiac Electrophysiology.

Chen X, Qian Z, Zou F, Wang Y, ... Vijayaraman P, Zou J
Background
Left bundle branch pacing (LBBP) is a new near-physiological pacing modality. Distinguishing left ventricular septal only pacing (LVSP) from nonselective LBBP still needs clarification. This prospective study sought to establish a differentiation algorithm to confirm LBBP.
Methods and results
LBBP was attempted in consecutive patients. If direct LBB capture (LBBP) could not be confirmed, LVSP was considered to have been achieved. Intracardiac left ventricular (LV) activation sequence and activation time were analyzed using coronary sinus (CS) electrogram mapping. Electrophysiological parameters including S-CSmax, S-CSmin, LV lateral wall activation time, ΔLV and LBB potential were compared between LBBP and LVSP. Stimulated LV activation time (S-LVAT) and stimulated QRS duration (S-QRSd) were also compared between the two groups. Multivariate logistic regression analysis was used to develop a prediction algorithm for LBBP. Of the 43 prospectively enrolled patients, 27 underwent LBBP and 16 underwent LVSP. All LBBP patients showed identical LV activation sequence to their intrinsic rhythm while no LVSP patients maintained their intrinsic sequence. S-CSmax, ΔLV, LV lateral wall activation time and S-LVAT during LBBP were significantly shorter than those during LVSP. Combining LBB potential with S-LVAT had the largest area under the curve (AUC) of 0.985 for confirming LBBP with a sensitivity of 95.2% and a specificity of 93.7%.
Conclusions
Compared with LVSP, LBBP preserves normal LV activation sequence and better electrical synchrony. Combination of LBB potential with S-LVAT can be an effective and practical model to distinguish LBBP from LVSP during implantation in patients with normal LBB activation. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jan 2022; epub ahead of print

Comparing the Safety and Effectiveness of Dedicated Radiofrequency Transseptal Wires to Electrified Metal Guidewires.

Wasserlauf J, Knight BP
Background
Application of electrocautery to a metal guidewire is used by some operators to perform transseptal puncture (TSP). Commercially available dedicated radiofrequency guidewires (RF) may represent a better alternative. This study compares safety and effectiveness of electrified guidewires to a dedicated RF wire.
Methods
TSP was performed on freshly excised porcine hearts using an electrified 0.014\" or 0.032\" guidewire under various power settings and was compared to TSP using a dedicated RF wire with 5W power (0.035\" VersaCross RF System, Baylis Medical, Montreal, Canada). The primary endpoint was the number of attempts required to achieve TSP. Secondary endpoints included the rate of TSP failure, TSP consistency, effect of the distance between tip of the guidewire and the tip of the dilator, effect of RF power output level. Qualitative secondary endpoints included tissue puncture defect appearance, thermal damage to the TSP guidewire or dilator, and tissue temperature using thermal imaging.
Results
The RF wire required on average 1.10 ± 0.47 attempts to cross the septum. The 0.014\" electrified guidewire required an overall mean of 2.17 ± 2.36 attempts (2.0 times as many as the RF wire; p<0.01), and the 0.032\" electrified guidewire required an overall mean of 3.90 ± 2.93 attempts (3.5 times as many as the RF wire; p<0.01). Electrified guidewires had a higher rate of TSP failure, and caused larger defects and more tissue charring than the RF wire. Thermal analysis showed higher temperatures and a larger area of tissue heating with electrified guidewires than the RF wire.
Conclusion
Fewer RF applications were required to achieve TSP using a dedicated RF wire compared to an electrified guidewire. Smaller defects and lower tissue temperatures were also observed using the RF wire. Electrified guidewires required greater energy delivery and were associated with equipment damage and tissue charring, which may present a risk of thrombus, thermal injury or scarring. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jan 2022; epub ahead of print

Pulsed field ablation combined with ultra-high-density mapping in patients undergoing catheter ablation for atrial fibrillation: practical and electrophysiological considerations.

Gunawardene MA, Schaeffer BN, Jularic M, Eickholt C, ... Hartmann J, Willems S
Background
Pulsed field ablation (PFA) yields a novel ablation technology for atrial fibrillation (AF). PFA lesions promise to be highly durable, however clinical data on lesion characteristics are still limited.
Objective
This study sought to investigate PFA lesion creation with ultra-high-density (UHDx) mapping.
Methods
Consecutive AF patients underwent PFA-based pulmonary vein isolation (PVI) using a multispline catheter (Farwave, Farapulse Inc). Additional ablation, including left atrial posterior wall isolation (LAPWI) and mitral isthmus isolation (MI) were performed in a subset of persistent AF patients. Extent of PFA-lesions and decrease of LA-voltage were assessed with pre- and post PFA UHDx-mapping (Orion^TM catheter and Rhythmia^TM 3D-mapping system, Boston Scientific).
Results
In 20 patients, acute PVI was achieved in 80/80 PVs, LAPW isolation in 9/9 patients, MI isolation in 2/2 (procedure time: 123±21.6minutes, fluoroscopy time: 19.2±5.5minutes). UHDx-mapping subsequent to PVI revealed early PV-reconnection in 5 case (5/80, 6.25%). Gaps were located at the anterior-superior PV ostia and were successfully targeted with additional PFA. Repeat UHDx mapping after PFA revealed significant decrease of voltage along the PV ostia (1.67±1.36mV vs. 0.053±0.038mV, P<0.0001) with almost no complex electrogram-fractionation at the lesion border zones. PFA-catheter visualization within the mapping system was feasible in 17/19 (84.9%) patients and adequate in 92.9% of ablation sites.
Conclusion
For the first time illustrated by UHDx mapping, PFA creates wide antral circumferential lesions and homogenous LAPW isolation with depression of tissue voltage to a minimum. Although with a low incidence, early PV reconnection can still occur also in the setting of PFA. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jan 2022; epub ahead of print

Taking the \"Pulse\" of Pulsed Field Ablation: Real-World Experience.

Baykaner T, Fazal M, Verma A
Atrial fibrillation (AF) ablation is the cornerstone of therapy for symptomatic AF, with now increasing data on the safety and efficacy of this approach over medical management in improving quality of life, decreasing rates of stroke, cardiac hospitalizations and providing mortality benefit in several populations This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jan 2022; epub ahead of print

Catheter ablation of ventricular tachycardia in patients with postinfarction left ventricular aneurysm.

Amin M, Farwati M, Hilaire E, Siontis KC, ... Asirvatham SJ, Killu AM
Background
While ventricular tachycardia (VT) in the setting of postmyocardial infarction left ventricular aneurysms (LVA) is not uncommonly encountered, there is a scarcity of data regarding the safety, efficacy, and outcomes of ablation of VT in this subset of patients.
Methods
Our study included consecutive patients aged 18 years or older with postmyocardial infarction LVA who presented to Mayo Clinic for catheter ablation of VT between 2002 and 2018.
Results
Of 34 patients, the mean age was 70.4 ± 9.1 years; 91% were male. Mean LVEF was 29 ± 9.7% and left ventricular end-diastolic dimension was 64.9 ± 6.6 mm. The site of the LVA was apical in 21 patients (62%). Fifteen patients (44%) presented with electrical storm or incessant VT. Nine patients (26%) had a history of intracardiac thrombus. All except for one patient had at least one VT originating from the aneurysm. The mean number of VTs was 2.9 ± 1.7. All patients underwent ablation at the site of the aneurysm. Ablation outside the aneurysm was performed in 13 patients (38%). Low-voltage fractionated potentials and/or late potentials at the aneurysmal site were present in all cases. Complete elimination of all VTs was achieved in 18 (53%), while the elimination of the clinical VT with continued inducibility of nonclinical VTs was achieved in a further 11 patients (32%). Two patients developed cardiac tamponade requiring pericardiocentesis. During a mean follow-up period of 2.3 ± 2.4 years, 11 patients (32%) experienced VT recurrence. Freedom from all-cause mortality at 1-year follow-up was 94%.
Conclusion
Radiofrequency catheter ablation targeting the aneurysmal site is a feasible and reasonably effective management strategy for clinical VTs in patients with postinfarction LVA.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3156-3164

His-Purkinje conduction system pacing: A systematic review and network meta-analysis in bradycardia and conduction disorders.

Qu Q, Sun JY, Zhang ZY, Kan JY, ... Li F, Wang RX
Background
His-Purkinje conduction system pacing (HPCSP) has emerged as an effective alternative to overcome the limitations of right ventricular pacing (RVP) via physiological left ventricular activation, but there remains a paucity of comparative information for His bundle pacing (HBP) and left bundle branch pacing (LBBP).
Methods
A Bayesian random-effects network analysis was conducted to compare the relative effects of HBP, LBBP, and RVP in patients with bradycardia and conduction disorders. PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from database inception until September 21, 2021.
Results
Twenty-eight studies involving 4160 patients were included in this meta-analysis. LBBP significantly improved success rate, pacing threshold, pacing impedance, and R-wave amplitude compared with HBP. LBBP also demonstrated a nonsignificant trend towards superior outcomes of lead complications, heart failure hospitalization, atrial fibrillation, and all-cause death. However, HBP was associated with significantly shorter paced QRS duration relative to LBBP. Despite higher success rates, shorter procedure/fluoroscopy duration, and fewer lead complications, patients receiving RVP were more likely to experience reduced left ventricular ejection fraction, longer paced QRS duration, and higher rates of heart failure hospitalization than those receiving HPCSP. No statistical differences were observed in the remaining outcome measures.
Conclusions
This network meta-analysis demonstrates the efficacy and safety of HPCSP for the treatment of bradycardia and conduction disorders, with differences in pacing parameters, electrophysiology characteristics, and clinical outcomes between HBP and LBBP. Larger-scale, long-term comparative studies are warranted for further verification.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3245-3258

Characterization of the electrophysiological substrate in patients with Barlow\'s disease.

Vergara P, Scarfò I, Esposito A, Colantoni C, ... Della Bella P, La Canna G
Background
Myxomatous mitral valve prolapse (MVP) and mitral-annular disjunction (Barlow disease) are at-risk for ventricular arrhythmias (VA). Fibrosis involving the papillary muscles and/or the infero-basal left ventricular (LV) wall was reported at autopsy in sudden cardiac death (SCD) patients with MVP.
Objectives
We investigated the electrophysiological substrate subtending VA in MVP patients with Barlow disease phenotype.
Methods
Twenty-three patients with VA were enrolled, including five with syncope and four with a history of SCD. Unipolar (Uni < 8.3 mV) and bipolar (Bi < 1.5 mV) low-voltage areas were analyzed with electro-anatomical mapping (EAM), and VA inducibility was evaluated with programmed ventricular stimulation (PES). Electrophysiological parameters were correlated with VA patterns, electrocardiogram (ECG) inferior negative T wave (nTW), and late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance.
Results
Premature ventricular complex (PVC) burden was 12 061.9 ± 12 994.6/24 h with a papillary-muscle type (PM-PVC) in 18 patients (68%). Twelve-lead ECG showed nTW in 12 patients (43.5%). A large Uni less than 8.3 mV area (62.4 ± 45.5 cm² ) was detected in the basal infero-lateral LV region in 12 (73%) patients, and in the papillary muscles (2.2 ± 2.9 cm² ) in 5 (30%) of 15 patients undergoing EAM. A concomitant Bi less than 1.5 mV area (5.0 ± 1.0 cm² ) was identified in two patients. A history of SCD, and the presence of nTW, and LGE were associated with a greater Uni less than 8.3 mV extension: (32.8 ± 3.1 cm² vs. 9.2 ± 8.7 cm² ), nTW (20.1 ± 11.0 vs. 4.1 ± 3.8 cm² ), and LGE (19.2 ± 11.7 cm² vs. 1.0 ± 2.0 cm² , p = .013), respectively. All patients with PM-PVC had a Uni less than 8.3 mV area. Sustained VA (ventricular tachycardia 2 and VF 2) were induced by PES only in four patients (one with resuscitated SCD).
Conclusions
Low unipolar low voltage areas can be identified with EAM in the basal inferolateral LV region and in the papillary muscles as a potential electrophysiological substrate for VA and SCD in patients with MVP and Barlow disease phenotype.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3179-3186

Efficacy and tolerability of quinidine as salvage therapy for monomorphic ventricular tachycardia in patients with structural heart disease.

Deshmukh A, Larson J, Ghannam M, Saeed M, ... Bogun F, Liang JJ
Introduction
Quinidine is an effective therapy for a subset of polymorphic ventricular tachycardia and ventricular fibrillation (VF) syndromes; however, the efficacy of quinidine in scar-related monomorphic ventricular tachycardia (MMVT) is unclear.
Methods and results
Between 2009 and 2020 a single VT referral center, a total of 23 patients with MMVT and structural heart disease (age 66.7 ± 10.9, 20 males, 15 with ischemic cardiomyopathy, mean LVEF 22.2 ± 12.3%, 9 with left ventricular assist device [LVAD]) were treated with quinidine (14 quinidine gluconate; 996 ± 321 mg, 8 quinidine sulfate; 1062 ± 588 mg). Quinidine was used in combination with other antiarrhythmics (AAD) in 19 (13 also on amiodarone). All patients previously failed >1 AAD (amiodarone 100%, mexiletine 73%, sotalol 32%, other 32%) and eight had prior ablations (median of 1.5). Quinidine was initiated in the setting of VT storm despite AADs (6), inability to tolerate other AADs (4), or recurrent VT(12). Ventricular arrhythmias recurred despite quinidine in 13 (59%) patients at a median of 26 (4-240) days after quinidine initiation. In patients with recurrent MMVT, VT cycle length increased from 359 to 434 ms (p = .02). Six (27.3%) patients remained on quinidine at 1 year with recurrence of ventricular arrhythmias in all. The following adverse effects were seen: gastrointestinal side effects (6), QT prolongation (2), rash (1), thrombocytopenia (1), neurologic side effects (1). One patient discontinued due to cost.
Conclusion
Quinidine therapy has limited tolerability and long-term efficacy when used in the management of amiodarone-refractory scar-related MMVT.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3173-3178

Actual tissue temperature during ablation index-guided high-power short-duration ablation versus standard ablation: Implications in terms of the efficacy and safety of atrial fibrillation ablation.

Otsuka N, Okumura Y, Kuorkawa S, Nagashima K, ... Takahashi R, Taniguchi Y
Background
Actual in vivo tissue temperatures and the safety profile during high-power short-duration (HPSD) ablation of atrial fibrillation have not been clarified.
Methods
We conducted an animal study in which, after a right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We recorded tissue temperatures during a 50 W-HPSD ablation and 30 W-standard ablation targeting an ablation index (AI) of 400 (5-15 g contact force).
Results
Maximum tissue temperatures reached with HSPD ablation were significantly higher than that reached with standard ablation (62.7 ± 12.5 vs. 52.7 ± 11.4°C, p = 0.033) and correlated inversely with the distance between the catheter tip and thermocouple, regardless of the power settings (HPSD: r = -0.71; standard: r = -0.64). Achievement of lethal temperatures (≥50°C) was within 7.6 ± 3.6 and 12.1 ± 4.1 s after HPSD and standard ablation, respectively (p = 0.003), and was best predicted at cutoff points of 5.2 and 4.4 mm, respectively. All HPSD ablation lesions were transmural, but 19.2% of the standard ablation lesions were not (p = 0.011). There was no difference between HPSD and standard ablation regarding the esophageal injury rate (30% vs. 33.3%, p > 0.99), with the injury appearing to be related to the short distance from the catheter tip.
Conclusions
Actual tissue temperatures reached with AI-guided HPSD ablation appeared to be higher with a greater distance between the catheter tip and target tissue than those with standard ablation. HPSD ablation for <7 s may help prevent collateral tissue injury when ablating within a close distance.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:55-63

Characteristics and optimal ablation settings of a novel, contact-force sensing and local impedance-enabled catheter in an ex vivo perfused swine ventricle model.

Tsutsui K, Kawano D, Mori H, Kato R, ... Muramatsu T, Matsumoto K
Background
Local impedance (LI) has emerged as a new technology that informs on electrical catheter-tissue coupling during radiofrequency (RF) ablation. Recently, IntellaNav StablePoint, a novel LI-enabled catheter that equips contact force (CF) sensing, has been introduced. Although StablePoint and its predecessor IntellaNav MiFi OI share the common technology that reports LI, distinct mechanics for LI sensing between the two products raise a concern that the LI-RF lesion formation relationship may differ.
Methods
In an ex vivo swine cardiac tissue model, we investigated the initial level and range of a reduction in LI during a 60-s RF ablation and the resultant lesion characteristics at nine combinations of three energy power (30, 40, and 50 W) and CF (10, 30, and 50 g) steps. Correlations and interactions between CF, LI, wattage, and formed lesions were analyzed. Incidence of achieving LI drop plateau and that of a steam pop were also determined.
Results
Positive correlations existed between CF and initial LI, CF and absolute/relative LI drop, CF and lesion volume, and LI drop and lesion volume. At the same LI drop, wattage-dependent gain in lesion volume was observed. Steam pops occurred in all CF steps and the prevalence was highest at 50 W. LI drop predicted a steam pop with a cutoff value at 89Ω.
Conclusion
In StablePoint, wattage crucially affects LI drop and lesion volume. Because 30 W ablation may by underpowered for intramural lesion formation and 50 W often resulted in a steam pop, 40 W appears to achieve the balance between the safety and efficacy.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3187-3194

Use of a novel 4D intracardiac echocardiography catheter to guide interventional electrophysiology procedures.

Kaplan RM, Narang A, Gay H, Gao X, ... Lin A, Knight BP
Introduction
Standard two-dimensional (2D), phased-array intracardiac echocardiography (ICE) is routinely used to guide interventional electrophysiology (EP) procedures. A novel four-dimensional (4D) ICE catheter (VeriSight Pro, Philips) can obtain 2D and three-dimensional (3D) volumetric images and cine-videos in real-time (4D). The purpose of this study was to determine the early feasibility and safety of this 4D ICE catheter during EP procedures.
Methods
The 4D ICE catheter was placed from the femoral vein in ten patients into various cardiac chambers to guide EP procedures requiring transseptal catheterization, including ablation for atrial fibrillation and left atrial appendage closure. 2D- and 3D-ICE images were acquired in real-time by the electrophysiologist. A dedicated imaging expert performed digital steering to optimize and postprocess 4D images.
Results
Eight patients underwent pulmonary vein isolation (cryoballoon in seven patients, pulsed field ablation in one, additional radiofrequency left atrial ablation in one). Two patients underwent left atrial appendage closure. High quality images of cardiac structures, transseptal catheterization equipment, guide sheaths, ablation tools, and closure devices were acquired with the ICE catheter tip positioned in the right atrium, left atrium, pulmonary vein, coronary sinus, right ventricle, and pulmonary artery. There were no complications.
Conclusion
This is the first experience of a novel deflectable 4D ICE catheter used to guide EP procedures. 4D ICE imaging is safe and allows for acquisition of high-quality 2D and 3D images in real-time. Further use of 4D ICE will be needed to determine its added value for each EP procedure type.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3117-3124

The surgical technique of the convergent procedure.

Yammine M, Puskas J, El Moheb M, Lattouf O
The convergent procedure is a newly developed hybrid ablation procedure that involves extensive epicardial ablation of the posterior left atrial wall followed by endocardial mapping and addition of pulmonary vein isolation. It is a team-based approach that provides a promising option for patients with persistent and permanent atrial fibrillation. In this manuscript, we present a detailed description of the surgical component of this procedure and include potential pitfalls based on our experience in performing it.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3221-3227

Mutational spectrum of congenital long QT syndrome in Turkey; identification of 12 novel mutations across KCNQ1, KCNH2, SCN5A, KCNJ2, CACNA1C, and CALM1.

Akgun-Dogan O, Ağaoğlu NB, K Demirkol Y, Doğanay L, Ergül Y, Karacan M
Introduction
Long QT syndrome (LQTS) is of great importance as it is the most common cause of sudden cardiac death in childhood. The diagnosis is made by the prolongation of the QTc interval on the electrocardiography. However, clinical heterogeneity and nondiagnostic QTc intervals may cause a delay in the diagnosis. In such cases, genetic tests such as next-generation sequencing (NGS) panel analysis enable a definitive diagnosis. We present the first study that aimed to expand the LQTS\'s mutational spectrum by NGS panel analysis from Turkey.
Methods
Fifty-seven unrelated patients with clinically diagnosed LQTS were investigated using an NGS panel that includes six LQTS-related genes. Clinical aspects, outcome, and molecular analysis results were reviewed.
Results
Pathogenic (53%)/likely pathogenic (23%)/variant of unknown significance (4%) variants were detected in any of the genes examined in 79% of the patients. Among all detected variants, KCNQ1(71%) was the most common gene, followed by SCN5A (11%), KCNH2 (10%), CALM1 (5%), and CACNA1C (3%). Twelve novel variants were detected. Among the variants in KCNQ1, the c.1097G>A variant was present in 42% of patients. This variant also composed 31% of the variants detected in all of the genes.
Conclusion
Our study expands the spectrum of the variations associated with LQTS with twelve novel variants in five genes. And also it draws attention to the frequency of the KCNQ1 c.1097G>A variant and forms the basis for new studies to determine the possible founder effect in the Turkish population. Furthermore, identifying new variants and clinical findings has importance in elaborating the roles of related genes in pathophysiology and determining the variable expression and incomplete penetration rates in this syndrome.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 02 Dec 2021; epub ahead of print

Physiologic lead placement with electroanatomic mapping: A case series.

Baman JR, Garg V, Kalluri AG, Wasserlauf J, ... Sharma PS, Verma N
Introduction
His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have emerged as attractive alternatives to traditional biventricular pacing to achieve cardiac resynchronization therapy. Early reported results have been inconsistent, particularly amongst patients in whom initial placement with traditional approaches has been unsuccessful or those with complex anatomy or congenital abnormalities. In this report, we describe the use of three-dimensional electroanatomic mapping (EAM) in five selected cases.
Methods
Five patients from multiple clinical sites underwent EAM-guided HBP or LBBAP by highly trained electrophysiologists with significant experience with conduction system pacing. Each patient in this series underwent EAM-guided conduction system pacing due to complex anatomy and/or prior failed lead implantation.
Results
EAM-guided lead implantation was successful in all five cases. Capture thresholds were relatively low and patients continued to have evidence of successful lead implantation with minimum 1-month follow-up. The fluoroscopy time varied, likely owing to the variable complexity of the cases.
Conclusions
The use of EAM, in combination with traditional intracardiac electrograms with or without fluoroscopy, allows more targeted and precise placement of leads for HBP and LBBAP pacing. Further investigation is needed to determine this strategy\'s long-term performance and to optimize patient selection.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3195-3202

Effect of DrOnedarone on atrial fibrosis progression and atrial fibrillation recurrence postablation: Design of the EDORA randomized clinical trial.

Marrouche NF, Dagher L, Wazni O, Akoum N, ... Hua H, EDORA Investigators
Background
Atrial fibrillation (AF) recurrence after catheter ablation is associated with worse outcomes and quality of life. Left atrial (LA) structural remodeling provides the essential substrate for AF perpetuation. Baseline extent and the progression of LA fibrosis after ablation are strong predictors of postprocedural AF recurrence. Dronedarone is an antiarrhythmic drug proven to efficiently maintain sinus rhythm.
Objective
We sought to investigate the effect of the antiarrhythmic drug Dronedarone in decreasing LA fibrosis progression and AF recurrence after ablation of AF patients.
Methods
EDORA (NCT04704050) is a multicenter, prospective, randomized controlled clinical trial. Patients with persistent or paroxysmal AF undergoing AF ablation will be randomized into Dronedarone versus placebo/standard of care. The co-primary outcomes are the recurrence of atrial arrhythmias (AA) within 13 months of follow-up after ablation and the progression of left atrial fibrosis postablation. All patients will receive a late-gadolinium enhancement magnetic resonance imaging at baseline, 3- and 12-month follow-up for the quantification of LA fibrosis and ablation-related scarring. AA recurrence and burden will be assessed using a 30-day ECG patch every 3 months with daily ECG recordings in between. Quality of life improvement is assessed using the AFEQT and AFSS questionnaires.
Conclusion
EDORA will be the first trial to assess the progression of LA structural remodeling after ablation and its association with Dronedarone treatment and ablation success in a randomized controlled fashion. The trial will provide insight into the pathophysiology of AF recurrence after ablation and may provide potential therapeutic targets to optimize procedural outcomes.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology Published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3203-3210

Electrocardiography of cardiac resynchronization therapy: Pitfalls and practical tips.

Manolis AS, Manolis AA, Manolis TA, Melita H
Cardiac resynchronization therapy (CRT) has been established as an effective mode of therapy in patients with heart failure and concurrent cardiac dyssynchrony, principally in the form of left bundle branch block (LBBB). The widespread use of CRT has ushered in a new landscape in 12-lead electrocardiography (ECG). ECG readings in these patients are most important to guide troubleshooting and also appropriate device programming, as well as discerning and managing nonresponders. A set of four ECG recordings need to accompany each patient with a CRT device, including a baseline ECG and recordings from monochamber (right and left ventricular) and biventricular pacing, which can be compared against a new recording to facilitate the evaluation of proper versus problematic biventricular pacing. Precordial ECG leads V1/2 acquired at the fourth intercostal space and limb leads, I and III, together with a quick assessment of perpendicular leads I and aVF to determine the quadrant of the QRS axis in the hexaxial diagram, may provide the framework for proper ECG interpretation in these patients. This important issue of 12-lead ECG in CRT patients is herein reviewed, pitfalls are pointed out and practical tips are provided for ECG reading to help recognize and manage problems with CRT device function. Furthermore, several pertinent ECG recordings and tabulated data are provided, and an algorithm is suggested that integrates prior algorithms and relevant information from current literature.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3228-3244

Perimitral atrial tachycardias dependent on residual nonligament of Marshall conduction.

Sato Y, Kusa S, Hachiya H, Yamao K, ... Hirano H, Sasano T
Introduction
Catheter ablation for perimitral atrial tachycardia (PMAT) that persists despite lateral mitral isthmus (LMI) ablation is challenging. The aim of this study was to identify the role of the ligament of Marshall (LOM) in PMATs that persist after LMI conduction block has been created, and evaluate the validity of ethanol infusion into the vein of Marshall (VOM) as treatment.
Methods and results
Sixteen consecutive PMATs in 13 patients that persisted despite apparent LMI conduction block, which was confirmed by ultrahigh-resolution mapping and entrainment pacing along the mitral annulus, were analyzed. PMATs were classified into two types based on the location of the endocardial breakthrough site: those utilizing the LOM (n = 13), which had a breakthrough site along with the LOM, and those not utilizing the LOM (n = 3), which had a breakthrough site at an anterior or posterior side of the LOM. Of the 16 PMATs, 5 PMATs (31%) were not suitable for ethanol infusion into the VOM because the LOM was not involved in the tachycardia circuit or because of the anatomy of the VOM. Fourteen PMATs (88%) were successfully terminated solely by breakthrough site ablation. At a mean follow-up period of 12 ± 9 months, 10 (77%) patients have remained free from atrial tachyarrhythmias.
Conclusion
In cases of PMAT following LMI ablation, epicardial conduction over the LMI can occur independently of the LOM. Ethanol infusion into the VOM in such cases would not abolish residual epicardial conduction. The anatomy of the VOM can also preclude the use of this method.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3146-3155

A reliable fossa ovalis impedance mapping for safer transseptal puncture: A new vision beyond voltage.

Pentimalli F, Cornara S, Astuti M, Bacino L, ... Errigo D, Bellone P
Introduction
Transseptal puncture (TSP) is widely used in clinical practice but is negatively affected by a nonneglectable rate of complications and X-ray exposure. To address these problems, we investigated whether or not impedance mapping could correctly identify fossa ovalis (FO) and safely guide TSP.
Methods and results
Electroanatomic mapping was performed with CARTO 3 system version 7 and a ThermoCool® SmartTouch® mapping catheter was employed. In each patient, an impedance map and a bipolar voltage map of the whole interatrial septum were collected, acquiring at least 150 points with a contact force ≥2 g and using the pattern matching filter. Thirty-five patients were enrolled. A low impedance area was clearly identified in 34 of them. In 30 patients (88%), the FO was located in the low impedance area. The map was obtained in sinus rhythm in 17 cases (50%); in 15 of these (88%), the TSP site, the patent foramen ovale, or the FO tenting area fell inside the low impedance area. The same numbers were observed when mapping during atrial fibrillation.
Conclusion
To the best of our knowledge, this is the first study that provides the reliability and reproducibility of impedance mapping in identifying FO, an affordable and feasible tool that could be potentially introduced into clinical practice.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3270-3274

Novel approach to intracardiac defibrillator placement in patients with atriopulmonary Fontan: Ventricular defibrillation with an atrial positioned ICD lead.

Padanilam MS, Ahmed AS, Clark BA, Mozes JI, Steinberg LA
Introduction
The Fontan procedure, used to palliate univentricular physiology, eliminates direct venous access to the ventricle and complicates implantable cardioverter-defibrillator (ICD) placement.
Methods and results
We describe two patients with Fontan palliation who underwent a novel transvenous approach to ICD placement. The approach uses a transvenous bipolar lead placed in a coronary sinus branch for ventricular sensing, and a defibrillation lead placed in the right atrium for atrial sensing and ventricular defibrillation.
Conclusion
Transvenous ICD implantation is possible in some patients with an atriopulmonary Fontan. This approach avoids a redo sternotomy for epicardial leads and excludes the need for lead placement in the systemic circulation.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3275-3278

Ventricular arrhythmia ablation in the presence of mechanical valve utilization and complications of catheter ablation for ventricular arrhythmia in patients with mechanical prosthetic valves.

Rozen G, Elbaz-Greener G, Andria N, Heist EK, ... Amir O, Marai I
Background
Catheter ablation (CA) for ventricular arrhythmias (VAs) is increasingly utilized in recent years. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for VAs in patients with mechanical valve (MV) prosthesis.
Methods
We drew data from the US National Inpatient Sample database to identify cases of VA ablations, including premature ventricular contraction and ventricular tachycardia, in patients with MVs, between 2003 and 2015. Sociodemographic and clinical data were collected and the incidence of catheter ablation complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity-matched cohort of patients without prior valve surgery.
Results
The study population included a weighted total of 647 CA cases in patients with prior MVs. The annual number of ablations almost doubled, from 34 ablations on average during the \"early years\" (2003-2008) to 64 on average during the \"late years\" (2009-2015) of the study (p = .001). Length of stay at the hospital did not differ significantly between patients with MVs and 649 matched patients without prior MVs (5.4 ± 0.4, 4.7 ± 0.3 days, respectively, p = .12). The data revealed a trend toward a higher incidence of complications (12.6% vs. 7.5% respectively, p = .14) and mortality (3.7% vs. 0.7%, respectively, p = .087) among patients with MVs compared to the matched control group, not reaching statistical significance.
Conclusion
The data show increased utilization of VA ablations in patients with MVs and a trend toward a higher incidence of in-hospital mortality and complications compared to the propensity-matched control group without MVs.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3165-3172

Cardioversion of recent-onset atrial fibrillation using intravenous antiarrhythmics: A European perspective.

Lévy S
Pharmacological cardioversion using intravenous antiarrhythmic agents is commonly indicated in symptomatic patients with recent-onset atrial fibrillation (AF). Except in hemodynamically unstable patients who require emergency direct current electrical cardioversion, for the majority of hemodynamically stable patients, pharmacological cardioversion represents a valid option and requires the clinician to be familiar with the properties and use of antiarrhythmic agents. The main characteristics of selected intravenous antiarrhythmic agents for conversion of recent-onset AF, the reported success rates, and possible adverse events are discussed. Among intravenous antiarrhythmics, flecainide, propafenone, amiodarone, sotalol, dofetilide, ibutilide, and vernakalant are commonly used. Antazoline, an old antihistaminic agent with antiarrhythmic properties was also reported to give encouraging results in Poland. Intravenous flecainide and propafenone are the only Class I agents still recommended by recent guidelines. Intravenous new Class III agents as dofetilide and ibutilide have high and rapid efficacy in converting AF to sinus rhythm but require strict surveillance with electrocardiogram (ECG) monitoring during and after intravenous administration because of the potential risk of QT prolongation and Torsades de Pointes, which can be prevented and properly managed. Vernakalant, a partial atrial selective was shown to have a high success rate and to be safe in real-life use.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Nov 2021; 32:3259-3269

Safety and durability of cavo-tricuspid isthmus linear ablation in the current era: Single-center 9-year experience from 1078 procedures.

Kakehashi S, Miyazaki S, Hasegawa K, Nodera M, ... Uzui H, Tada H
Background
Cavo-tricuspid isthmus (CTI) linear ablation is performed not only for atrial flutter (AFL) but empirically during atrial fibrillation (AF) ablation in real-world practice. 
Purpose:
We sought to evaluate the safety and durability of the CTI ablation. 
Methods:
This retrospective study included 1078 consecutive patients who underwent a CTI ablation. AFL was documented before or during the procedure in 249 (23.1%) patients, and an empirical CTI and AF ablation were performed in 829 (76.9%) patients. 
Results:
CTI block was successfully created in 1051 (97.5%) patients with a 10.3 ± 6.6 min total radiofrequency time. Repeat procedures were performed for recurrent arrhythmias in 187 (17.3%) patients at a median of 11.0 (5.0-30.0) months postprocedure, and conduction resumption was identified in 68/174 (39.1%). Among those undergoing a CTI ablation with an AF ablation, the durability was significantly higher in those with than without documented AFL (78.1% vs. 58.2%, p = .031).  The total radiofrequency time was significantly shorter (9.0 ± 5.3 vs. 10.0 ± 6.4 [mins], p = .024) and durability significantly higher (78.1 vs. 58.7[%], p = .043) in the large-tip than irrigated-tip catheter group. Iatrogenic AFL was observed after the empiric CTI ablation in 11 (1.3%) patients. Procedure-related complications occurred in 15 (1.4%) patients. Eight patients experienced coronary artery spasms, including one with ventricular fibrillation following ST elevation on the ward. The other six patients experienced transient atrioventricular block and one experienced cardiac tamponade requiring drainage. 
Conclusions:
Despite a high acute CTI ablation success, the conduction block durability was relatively low after the empiric ablation. An empiric CTI ablation at the time of the AF ablation is not recommended.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:40-45

Procedural and short-term results of electroanatomic-mapping-guided ganglionated plexus ablation by first-time operators: A multicenter study.

Aksu T, De Potter T, John L, Osorio J, ... Gupta D, Davila A
Introduction
Single-center observational studies have shown promising results with fragmented electrogram (FE)-guided ganglionated plexus (GP) ablation in patients with vagally mediated bradyarrhythmia (VMB). We aimed to compare the acute procedural characteristics during FE-guided GP ablation in patients with VMB performed by first-time operators and those of a single high-volume operator.
Methods and results
This international multicenter cohort study included data collected over 2 years from 16 cardiac hospitals. The primary operators were classified according to their prior GP ablation experience: a single high-volume operator who had performed > 50 GP ablation procedures (Group 1), and operators performing their first GP ablation cases (Group 2). Acute procedural characteristics and syncope recurrence were compared between groups. Forty-seven consecutive patients with VMB who underwent FE-guided GP ablation were enrolled, n = 31 in Group 1 and n = 16 in Group 2. The mean number of ablation points in each GP was comparable between groups. The ratio of positive vagal response during ablation on the left superior GP was higher in Group 1 (90.3% vs. 62.5%, p = .022). Ablation of the right superior GP increased heart rate acutely without any vagal response in 45 (95.7%) cases. The procedure time was longer in group 2 (83.4 ± 21 vs. 118.0 ± 21 min, respectively, p < .001). Over a mean follow-up duration of 8.0 ± 3 months (range 2-24 months), none of the patients suffered from syncope.
Conclusion
This multi-center pilot study shows for the first time the feasibility of FE-guided GP ablation across a large group of procedure-naïve operators.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:117-122

Endothelial function and atrial fibrillation: A missing piece of the puzzle?

Black N, Mohammad F, Saraf K, Morris G
Endothelial dysfunction, a term used to describe both the physical damage and dysregulated physiology of this endothelial lining, is an increasingly recognized pathophysiological state shared by many cardiovascular diseases. Historically, the role of endothelial dysfunction in atrial fibrillation (AF) was thought to be limited to mediating atrial thromboembolism. However, there is emerging evidence that endothelial dysfunction both promotes and maintains atrial arrhythmic substrate, predicts adverse outcomes, and identifies patients at high risk of recurrence following cardioversion and ablation therapy. Treatments targeted at improving endothelial function also represent a promising new therapeutic paradigm in AF. This review summarizes the current understanding of endothelial function in AF.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:109-116

Pregnancy in women with Brugada syndrome: Is there an increased arrhythmia risk? A case-series report.

van der Crabben SN, Kowsoleea AIE, Clur SB, Wilde AAM
Introduction
In some rare arrhythmia syndromes, arrhythmia risk in female patients increases during pregnancy, necessitating extra controls. We wanted to evaluate if the increased risk for arrhythmia during pregnancy applies in women with Brugada syndrome and their potentially affected fetuses.
Methods
A comprehensive literature search was performed on PubMed (MeSH search terms \"Brugada syndrome,\" \"pregnancy,\" \"parturition,\" \"labor,\" \"delivery,\" \"fetal death,\" and \"stillbirth\").
Results
Overall, six case reports with a total of six patients were identified. Of these six patients (three carriers of an SCN5A variant, three not tested), two women (both with unknown SCN5A status), developed severe cardiac events during pregnancy. The first patient, with a previous history of aborted sudden cardiac arrest at the age of 12 years, developed ventricular fibrillation (VF), while the other was diagnosed with Brugada syndrome postpartum because of nocturnal agonal respiration during pregnancy.
Conclusion
These (limited, heterogenous) cases suggest that women with Brugada syndrome (and their possibly affected fetuses), might have an overall low tendency to develop arrhythmias during pregnancy, but important data on risk factors (SCN5A status) are lacking. Arrhythmia risk during pregnancy seems to increase in probands and those who have previously experienced cardiac events. We suggest the use of risk stratification in these women to improve patient care, lower the emotional stress and physical burden for the pregnant mother, and lower health costs. Furthermore, we plead for SCN5A analysis in all these women for use of risk stratification and to enable cascade screening especially for specialized care in children carrying an SCN5A mutation.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:123-127

A histological study of the atria in patients with isolated rheumatic mitral regurgitation with and without atrial fibrillation.

Kalpana SR, Shenthar J, Padmanabhan D, Rai MK, ... Kalyani RN, Kamalapurkar G
Background
There is a high incidence of atrial fibrillation (AF) in patients with isolated rheumatic mitral regurgitation (MR). The histopathologic changes in the atria of patients with isolated rheumatic MR with and without AF are unknown.
Objectives
We aimed to determine the histological findings in patients with isolated severe rheumatic MR with and without AF.
Methods
Patients with severe isolated rheumatic MR undergoing valve replacement surgeries underwent endocardial biopsies from right atrial appendage, left atrial appendage, right free wall, left free wall, left posterior wall, and mitral valve. Group I consisted of patients in sinus rhythm (SR), and Group II included patients with AF. We analyzed and compared these 10 histological features in the biopsies of patients in Groups I and II.
Results
Of the 25 patients, 12 were in Group I and 13 in Group II. In Group I, patients had severe myocyte hypertrophy (60% vs. 18%, p = .04) that was significantly more in the right atrium (22.7% vs. 11.4%, p = .059). Interstitial adipose tissue deposition was more common in Group I (30% vs. 25%, p = .06). Interstitial fibrosis was evenly distributed at all sites without significant difference between the two groups. Group II patients had a higher prevalence and severity of vacuolar degeneration (91% vs. 60%, p = .09).
Conclusions
Patients with isolated severe rheumatic MR and AF have more vacuolar degeneration in the atrial tissue. Patients with SR have myocyte hypertrophy and interstitial adipose tissue deposition. Interstitial fibrosis is uniformly distributed in patients in SR and AF.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:32-39

Adverse events related to AtriCure EPi-Sense Coagulation Device-Analysis of the FDA MAUDE database.

Sheth AR, Al Yafeai Z, Dominic P
Introduction
The AtriCure EPi-Sense Device is used for the hybrid convergent procedure, an emerging treatment for persistent atrial fibrillation (AF) and long-standing persistent AF. However, data on the AE related to the EPi-Sense device are scarce.
Methods
Keyword \"EPI-SENSE\" was searched on the MAUDE database. There were 80 device reports from 2016 to 2020. After excluding reports when the device was not returned for evaluation, 79 device reports were included for final analysis.
Results
The adverse events (AE) were broadly classified into 11 categories. The most common complications were pericardial effusion (25.3%), stroke (17.7%), and atrioesophageal fistula (AEF) (8.9%). Death was reported in 15 (19%) cases, 3 of which were due to pulmonary embolism, 6 due to AEF, 3 due to unknown cause, 1 due to sepsis, 2 due to events related to acute renal failure.
Discussion
Pericardial effusion is a common AE reported in patients with convergence procedures and is well documented in the CONVERGE trial. The convergent procedure is unique in that the epicardial ablations are performed on the posterior wall with the radiofrequency probe directed towards the heart and away from the esophagus which in theory should reduce esophageal injuries. Despite that, a high number of AEF were noticed. Finally, there were also some reports of saline perfusion malfunction which can lead to injuries due to overheating.
Conclusion
This analysis of the AE related to the EPi-Sense device highlights several major AE that are previously unreported.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 08 Nov 2021; epub ahead of print

Electromagnetic interference from left ventricular assist devices detected in patients with implantable cardioverter-defibrillators.

Sheldon SH, Jazayeri MA, Pierpoline M, Mohammed M, ... Sauer AJ, Reddy YM
Introduction
Electromagnetic interference (EMI) from left ventricular assist devices (LVADs) can cause implantable cardioverter-defibrillator (ICD) oversensing. We sought to assess the frequency of inappropriate shocks/oversensing due to LVAD-related EMI and prospectively compare integrated (IB) versus dedicated bipolar (DB) sensing in patients with LVADs.
Methods
Single-center study in LVAD patients with Medtronic or Abbott ICDs between September 2017 and March 2020. We excluded patients that were pacemaker dependent. Measurements were obtained of IB and DB sensing and noise to calculate a signal-to-noise ratio (SNR). Device checks were reviewed to assess appropriate and inappropriate sensing events.
Results
Forty patients (age 52 ± 14 years, 75% men, 38% ischemic cardiomyopathy) were included with the median time between LVAD implantation and enrollment of 6.7 months (2.3, 11.4 months). LVAD subtypes included: HeartWare (n = 22, 55%), Heartmate II (n = 10, 25%), and Heartmate III (n = 8, 20%). Over a follow-up duration of 21.6 ± 12.9 months after LVAD implantation, 5% of patients (n = 2) had oversensing of EMI from the LVAD (both with HeartWare LVADs and Abbott ICDs) at 4 days and 10.8 months after LVAD implantation. Both patients underwent adjustment of ventricular sensing with resolution of oversensing and no further events over 5 and 15 months of further follow-up. The SNR was similar between IB and DB sensing (50 [29-67] and 57 [41-69], p = 0.89).
Conclusion
ICD oversensing of EMI from LVADs is infrequent and can be managed with reprogramming the sensitivity. There was no significant difference in the R-wave SNR with IB versus DB ICD leads.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:93-101

The established and the challenger: A direct comparison of current cryoballoon technologies for pulmonary vein isolation.

Moser F, Rottner L, Moser J, Schleberger R, ... Rillig A, Metzner A
Introduction
Cryoballoon (CB) ablation for pulmonary vein isolation (PVI) is an effective treatment of atrial fibrillation (AF). Recently, a novel cryoablation system was introduced. The aim of the study was to compare the safety, efficacy and biophysical characteristics of a novel cryoablation system (POLARx™; Boston Scientific) to a commonly used and clinically well characterized system (Arctic Front Advance Pro™, AFA; Medtronic).
Methods and results
Fifty consecutive patients with symptomatic AF, who underwent CB-based ablation with the POLARx were compared to 50 consecutive patients treated with the AFA. Acute PVI was achieved in 99.8% (POLARx 99.5%, AFA 100%, p = 1.00). Time to isolation (TTI) was comparable in both groups (POLARx 35 [27, 48] s, AFA 30 [21, 43] s, p = 0.165). The POLARx showed a lower balloon temperature at TTI (POLARx -44 [-50, -36] °C, AFA -31 [-38, -21] °C, p < 0.001) and lower nadir temperature (POLARx -60 [-65, -55] °C, AFA -48 [-54, -45] °C, p < 0.001). Procedure time (POLARx 80 [60, 105] min, AFA 62 [42, 80] min, p < 0.001), fluoroscopy time (POLARx 17 [13, 22] min, AFA 11 [7, 16] min, p < 0.001) and freeze cycles per patient (POLARx 5 [4, 6], AFA 4.5 [4, 5], p = 0.002) were higher in the POLARx group. Two cerebral ischemic events occurred in the POLARx group, two patients in each group had phrenic nerve injury.
Conclusion
Both systems enable effective isolation of pulmonary veins. The POLARx required longer procedure and fluoroscopy times. Larger, prospective and randomized studies are needed to assess long-term efficacy and safety of this technology.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:48-54

Patient acceptance of subcutaneous versus transvenous defibrillator systems: A multi-center experience.

Vicentini A, Bisignani G, De Vivo S, Viani S, ... Rordorf R, “S-ICD Rhythm Detect” Investigators
Background
The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an effective alternative to the transvenous ICD. No study has yet compared S-ICD and transvenous ICD by assessing patient acceptance as a patient-centered outcome.
Objective
To evaluate the patient acceptance of the S-ICD and to investigate its association with clinical and implantation variables. In patients with symptomatic heart failure and reduced ejection fraction (HFrEF), the acceptance of the S-ICD was compared with a control group of patients who received a transvenous ICD.
Methods
Patient acceptance was calculated with the Florida Patient Acceptance Survey (FPAS) which measures four factors: return to function (RTF), device-related distress (DRD), positive appraisal (PA), and body image concerns (BIC). The survey was administered 12 months after implantation.
Results
176 patients underwent S-ICD implantation. The total FPAS and the single factors did not differ according to gender, body habitus, or generator positioning. Patients with HFrEF had lower FPAS and RTF. Younger patients showed better RTF (75 [56-94] vs. 56 [50-81], p = .029). Patients who experienced device complications or device therapies showed higher DRD (40 [35-60] vs. 25 [10-50], p = .019). Patients with HFrEF receiving the S-ICD had comparable FPAS, RTF, DRD, and BIC to HFrEF patients implanted with the transvenous ICD while exhibited significantly better PA (88 [75-100] vs. 81 [63-94], p = .02).
Conclusions
Our analysis revealed positive patient acceptance of the S-ICD, even in groups at risk of more distress such as women or patients with thinner body habitus, and regardless of the generator positioning. Among patients receiving ICDs for HFrEF, S-ICD was associated with better PA versus transvenous ICD.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:81-89

Direction-aware mapping algorithms have minimal impact on bipolar voltage maps created using high-resolution multielectrode catheters.

Yavin HD, Sroubek J, Yarnitsky J, Bubar ZP, ... Basu S, Anter E
Introduction
Direction-aware mapping algorithms improve the accuracy of voltage mapping by measuring the maximal voltage amplitude recorded in the direction of wavefront propagation. While beneficial for stationary catheters, its utility for roving catheters collecting electrograms (EGMs) at multiple angles is unknown.
Objective
To compare the directional dependence of bipolar voltage amplitude between stationary and roving catheters.
Methods
In 10 swine, a transcaval ablation line with a gap was created. The gap was mapped using an array catheter (Optrell™; Biosense Webster). In Step 1, the array was kept stationary over the gap, and four voltage maps were created during activation of the gap from superior, inferior, septal, and lateral directions. In Step 2, four additional maps were created; however, the catheter was allowed to move with points acquired at multiple angles. In Step 3, the gap was remapped; however, bipoles were computed using a direction-aware mapping algorithm.
Results
In a stationary catheter position, bipolar voltage distribution was influenced by the direction of activation with maximal differences obtained between orthogonal directions 32% (13%-53%). However, roving the catheter produced similar bipolar voltage maps irrespective of the direction of activation 11% (5%-18%). A direction-aware mapping algorithm was beneficial for reducing the directional dependence of voltage maps created by stationary catheters but not by roving catheters.
Conclusion
The directional dependency of bipolar voltage amplitude is greatest when the catheter is stationary. However, when the catheter is allowed to rove and collect EGMs at multiple angles as occurs clinically, the directional dependence of bipolar voltage is minimal.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:73-80

Ablation Index-guided point-by-point ablation versus Grid annotation-guided dragging for pulmonary vein isolation: A randomized controlled trial.

Mulder MJ, Kemme MJB, Hopman LHGA, Hagen AMD, ... van Rossum AC, Allaart CP
Introduction
Radiofrequency (RF) atrial fibrillation (AF) ablation using a catheter dragging technique may shorten procedural duration and improve durability of pulmonary vein isolation (PVI) by creating uninterrupted linear ablation lesions. We compared a novel AF ablation approach guided by Grid annotation allowing for \"drag lesions\" with a standard point-by-point ablation approach in a single-center randomized study.
Methods
Eighty-eight paroxysmal or persistent AF patients were randomized 1:1 to undergo RF-PVI with either a catheter dragging ablation technique guided by Grid annotation or point-by-point ablation guided by Ablation Index (AI) annotation. In the Grid annotation arm, ablation was visualized using 1 mm³ grid points coloring red after meeting predefined stability and contact force criteria. In the AI annotation arm, ablation lesions were created in a point-by-point fashion with AI target values set at 380 and 500 for posterior/inferior and anterior/roof segments, respectively. Patients were followed up for 12 months after PVI using ECGs, 24-h Holter monitoring and a mobile-based one-lead ECG device.
Results
Procedure time was not different between the two randomization arms (Grid annotation 71 ± 19 min, AI annotation 72 ± 26 min, p = .765). RF time was significantly longer in the Grid annotation arm compared with the AI annotation arm (49 ± 8 min vs. 37 ± 8 min, respectively, p < .001). Atrial tachyarrhythmia recurrence was documented in 10 patients (23%) in the Grid annotation arm compared with 19 patients (42%) in the AI annotation arm with time to recurrence not reaching statistical significance (p = .074).
Conclusions
This study shows that a Grid annotation-guided dragging approach provides an alternative to point-by-point RF-PVI using AI annotation.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:64-72

A single-center experience with early adoption of physiologic pacing approaches.

Oates CP, Kawamura I, Turagam MK, Langan MN, ... Reddy VY, Koruth JS
Background
Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing.
Objective
To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center.
Methods
Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately 1 year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms, and impedance between 400 and 1200 Ω.
Results
The HBP group was younger with lower ejection fraction compared to LBBAP (73.2 ± 15.3 vs. 78.2 ± 9.2 years, p = .047; 51.0 ± 15.9% vs. 57.0 ± 13.1%, p = .044). Post-procedural QRS widths were similarly narrow (119.8 ± 21.2 vs. 116.7 ± 15.2 ms; p = .443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs. 96.4%, p = .001) and most recent follow-up (60.7% vs. 94.9%, p ≤ .001; at 399 ± 259 vs. 228 ± 124 days, p ≤ .001). More HBP patients required lead revision due to early battery depletion or concern for pacing failure (0% vs. 13.3%, at a mean of 664 days).
Conclusion
During initial adoption, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions compared with LBBAP.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 28 Nov 2021; epub ahead of print

Impact of comorbidities on atrial fibrillation and sudden cardiac death in hypertrophic cardiomyopathy.

Sridharan A, Maron MS, Carrick RT, Madias CA, ... Maron BJ, Rowin EJ
Background
The impact of comorbid disease states on the development of atrial and ventricular arrhythmias in patients with hypertrophic cardiomyopathy (HCM) remains unresolved.
Objective
Evaluate the association of comorbidities linked to arrhythmias in other cardiovascular diseases (e.g., obesity, systemic hypertension, diabetes, obstructive sleep apnea, renal disorders, tobacco, and alcohol use) to atrial fibrillation (AF) and sudden cardiac death (SCD) events in a large cohort of HCM patients.
Methods
A total  of 2269 patients, 54 ± 15 years of age, 1392 males, were evaluated at the Tufts HCM Institute between 2004 and 2018 and followed for an average of 4 ± 3 years for new-onset clinical AF and SCD events (appropriate defibrillation for ventricular tachyarrhythmias, resuscitated cardiac arrest, or SCD).
Results
One or more comorbidity was present in 75% of HCM patients, including 50% with ≥2 comorbidities, most commonly obesity (body mass index [BMI] ≥ 30 kg/m² ) in 43%. New-onset atrial fibrillation developed in 11% of our cohort (2.6%/year). On univariate analysis, obesity was associated with a 1.7-fold increased risk for AF (p = .03) with 12% of obese patients developing AF (3.3%/year) as compared to 7% of patients with BMI < 25 kg/m² (1.6%/year; p = .006). On multivariate analysis, age and LA transverse dimension emerged as the only variables predictive of AF. Comorbidities, including obesity, were not independently associated with AF development (p > .10 for each). SCD events occurred in 3.3% of patients (0.8%/year) and neither obesity nor other comorbidities were associated with increased risk for SCD (p > .10 for each).
Conclusions
In adult HCM patients comorbidities do not appear to impact AF or SCD risk. Therefore, for most patients with HCM, adverse disease related events of AF and SCD appear to be primarily driven by underlying left ventricular and atrial myopathy as opposed to comorbidities.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:20-29

Bachmann\'s bundle-ridge related biatrial tachycardia with a long epicardial circuit.

Shimeno K, Tamura S, Hayashi Y, Abe Y, Naruko T
Biatrial tachycardia (BiAT), involving Bachmann\'s bundle in the circuit, has sometimes been observed after mitral anterior line ablation. In this article, we present a case of BiAT, involving a long epicardial circuit, composed of Bachmann\'s bundle and the left atrial ridge (LAR). We discuss the optimal ablation technique for this tachycardia based on our experience in addition to the relationship between Bachmann\'s bundle and the LAR. Furthermore, the evaluation method for the mitral anterior block line is also discussed.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:134-136

Left bundle branch area pacing guided by continuous uninterrupted monitoring of unipolar pacing characteristics.

Gillis K, O\'Neill L, Wielandts JY, Hilfiker G, ... Tavernier R, le Polain de Waroux JB
Introduction
During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics confirms LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation.
Methods
Thirty patients (mean age 76 ± 14 years) were implanted with a stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (comparison-group) conventional implantation with interrupted unipolar pacing was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (uninterrupted-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were evaluated.
Results
In the comparison group, LS and CP-pacing impedances were highly correlated (R²  = 0.95, p < .0001, bias 12 ± 37 Ω) with comparable sensed electrograms and paced QRS morphologies. In the uninterrupted group, continuous LS-pacing allowed beat-to-beat monitoring of impedance and QRS morphology to guide implantation. This resulted in successful LBBAP in all patients, after a mean of 1 ± 0 attempts, with mean threshold 0.81 ± 0.4 V, median sensing 6.5 mV [IQR 4.4-9.5], and mean impedance 624 ± 101 Ω. Positive LBBAP-criteria were seen in all patients with median paced QRS duration of 120 ms [IQR 112-152 ms] and median pLVAT 73 ms [IQR 68-80.5 ms]. No septal perforation occurred.
Conclusion
Unipolar pacing from the LS allows accurate determination of pacing impedance and generates similar paced QRS morphologies and sensed electrograms to CP pacing. Continuous LS pacing allows real-time monitoring of impedance and paced QRS morphology, which facilitates safe and successful LBBAP lead implantation.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 28 Nov 2021; epub ahead of print

Relationship between luminal esophageal temperature and volume of esophageal injury during RF ablation: In silico study comparing low power-moderate duration vs. high power-short duration.

Pérez JJ, González-Suárez A, Maher T, Nakagawa H, d\'Avila A, Berjano E
Objective
To model the evolution of peak temperature and volume of damaged esophagus during and after radiofrequency (RF) ablation using low power-moderate duration (LPMD) versus high power-short duration (HPSD) or very high power-very short duration (VHPVSD) settings.
Methods
An in silico simulation model of RF ablation accounting for left atrial wall thickness, nearby organs and tissues, as well as catheter contact force. The model used the Arrhenius equation to derive a thermal damage model and estimate the volume of esophageal damage over time during and after RF application under conditions of LPMD (30 W, 20 s), HPSD (50 W, 6 s), and VHPVSD (90 W, 4 s).
Results
There was a close correlation between maximum peak temperature after RF application and volume of esophageal damage, with highest correlation (R²  = 0.97) and highest volume of esophageal injury in the LPMD group. A greater increase in peak temperature and greater relative increase in esophageal injury volume in the HPSD (240%) and VHPSD (270%) simulations occurred after RF termination. Increased endocardial to esophageal thickness was associated with a longer time to maximum peak temperature (R²  > 0.92), especially in the HPSD/VHPVSD simulations, and no esophageal injury was seen when the distances were >4.5 mm for LPMD or >3.5 mm for HPSD.
Conclusion
LPMD is associated with a larger total volume of esophageal damage due to the greater total RF energy delivery. HPSD and VHPVSD shows significant thermal latency (resulting from conductive tissue heating after RF termination), suggesting a requirement for fewer esophageal temperature cutoffs during ablation.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 01 Dec 2021; epub ahead of print

Bayesian network meta-analysis comparing cryoablation, radiofrequency ablation, and antiarrhythmic drugs as initial therapies for atrial fibrillation.

Elsayed M, Abdelfattah OM, Sayed A, Prasad RM, ... Wazni OM, Hussein AA
Background
Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy.
Objective
To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF.
Methods
MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random-effects Bayesian network meta-analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI).
Results
Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10-0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16-1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06-1.96) nor RFA (OR: 0.34; 95% CrI: 0.07-1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13-0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44-1.39) nor RFA (OR: 1.45; 95% CrI: 0.67-3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01-0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44-1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events.
Conclusion
Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 01 Dec 2021; epub ahead of print

Cost-effectiveness of catheter ablation versus medical therapy for the treatment of atrial fibrillation in the United Kingdom.

Leung LWM, Imhoff RJ, Marshall HJ, Frame D, ... Taylor H, Gallagher MM
Introduction
Research evidence has shown that catheter ablation is a safe and superior treatment for atrial fibrillation (AF) compared to medical therapy, but real-world practice has been slow to adopt an early interventional approach. This study aims to determine the cost effectiveness of catheter ablation compared to medical therapy from the perspective of the United Kingdom.
Methods
A patient-level Markov health-state transition model was used to conduct a cost-utility analysis. The population included patients previously treated for AF with medical therapy, including those with heart failure (HF), simulated over a lifetime horizon. Data sources included published literature on utilization and cardiovascular event rates in real world patients, a systematic literature review and meta-analysis of randomized controlled trials for AF recurrence, and publicly available government data/reports on costs.
Results
Catheter ablation resulted in a favorable incremental cost-effectiveness ratio (ICER) of £8614 per additional quality adjusted life years (QALY) gained when compared to medical therapy. More patients in the medical therapy group failed rhythm control at any point compared to catheter ablation (72% vs. 24%) and at a faster rate (median time to treatment failure: 3.8 vs. 10 years). Additionally, catheter ablation was estimated to be more cost-effective in patients with AF and HF (ICER = £6438) and remained cost-effective over all tested time horizons (10, 15, and 20 years), with the ICER ranging from £9047-£15 737 per QALY gained.
Conclusion
Catheter ablation is a cost-effective treatment for atrial fibrillation, compared to medical therapy, from the perspective of the UK National Health Service.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 10 Dec 2021; epub ahead of print

Improvement of left ventricular function with surgical revascularization in patients eligible for implantable cardioverter-defibrillator.

Adabag S, Carlson S, Gravely A, Buelt-Gebhardt M, Madjid M, Naksuk N
Introduction
Left ventricular ejection fraction (EF) ≤ 35% is the cornerstone criterion for implantable cardioverter-defibrillator (ICD) eligibility. Improvement in EF may occur in ICD-eligible patients after coronary artery bypass graft surgery (CABG). However, the incidence, predictors, and outcomes of this process are unclear.
Methods and results
We studied 427 patients with EF ≤ 35% who underwent CABG in the Surgical Treatment for Ischemic Heart Failure (STICH) trial and had a systematic pre- and postoperative (4 months) EF assessment using the identical cardiac imaging modality. All imaging studies were interpreted at a core laboratory. Improvement in EF was defined as postoperative EF > 35% and >5% absolute improvement from baseline. Of the 427 patients (mean age 61.8 ± 9.5 and 50 women), 125 (29.2%) had EF improvement. Their mean EF increased from 26.8% (±5.8%) to 43.3% (±6.5%) (p < .0001). EF improvement occurred in only 20% of patients with a preoperative EF < 25%. The odds of EF improvement were 1.96 times higher (95% confidence interval [CI]: 0.91-4.23, p = .09) in patients with myocardial viability. In adjusted analyses, EF improvement was associated with a significantly lower risk of all-cause mortality (hazard ratio [HR]: 0.58, 95% CI: 0.35-0.96; p = .03) and heart failure mortality (HR: 0.31, 95% CI: 0.11-0.87; p = .027).
Conclusion
Nearly 1/3rd of ICD-eligible patients undergoing CABG had significant improvement in EF, obviating the need for primary prevention ICD implantation. These results provide patients and clinicians data on the likelihood of ICD eligibility after CABG and support the practice of reassessment of EF after revascularization.

© 2021 Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

J Cardiovasc Electrophysiol: 10 Dec 2021; epub ahead of print

Catheter ablation versus medical therapy for atrial fibrillation: Penny-wise Pound-foolish.

Kowlgi GN, Deshmukh AJ
Catheter ablation for atrial fibrillation has emerged as a mainstay for the management of atrial fibrillation. It has been shown to be clinically effective and cost-effective in multiple trials.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 10 Dec 2021; epub ahead of print

Catheter knot around the mitral valve apparatus: An exceptional complication of remote magnetic navigation.

Benali K, Hammache N, Sellal JM, Mazen E, de Chillou C
Remote magnetic navigation (RMN) is as safe and effective as manual navigation for catheter ablation of ventricular arrhythmias. This case is the first description of a soft-tip ablation catheter entrapment in the mitral valve apparatus during an RMN ablation procedure. The tight knot created by the catheter around a mitral valve chordae required surgical removal. This complication, which has never been reported before, highlights the need for closer fluoroscopic monitoring when performing catheter loops inside the ventricles when using the RMN system.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Dec 2021; 33:137-139

Outcomes of posterior wall isolation with pulmonary vein isolation for paroxysmal atrial fibrillation.

Jankelson L, Garber L, Shulman E, Cohen RB, ... Aizer A, Chinitz L
Introduction
Prior studies have shown that addition of posterior wall isolation (PWI) may reduce atrial fibrillation recurrence in patients with persistent atrial fibrillation. No data on PWI in paroxysmal AF (pAF) patients with normal left atrial voltage is available, to date.
Objective
This study sought to evaluate the efficacy of PWI in addition to pulmonary vein isolation (PVI) in patients presenting with pAF and normal left atrial voltage.
Methods
Consecutive patient registry analysis was performed on all patients with pAF and normal left atrial voltage undergoing initial radiofrequency ablation from November 1, 2018 to November 15, 2019. Primary endpoint was recurrence of atrial arrhythmia including AF, atrial tachycardia (AT), or atrial flutter (AFL).
Results
A total of 321 patients were studied, 214 in the PVI group and 107 in the PWI + PVI group. Recurrence of any atrial arrhythmia occurred in 18.2% of patients in the PVI group and 16.8% in the PVI + PWI cohort (p = 0.58). At 1 year, recurrence was 14.0% in the PVI group and 15.0% in the PWI + PVI group (p = 0.96). There was a lower AT/AFL recurrence in the PVI + PWI group, not reaching significance (3.7% in the PWI + PVI group vs. 7.9% in PVI group, p = 0.31). Need for carina lesions predicted recurrence in the PVI-only group.
Conclusions
Addition of PWI to PVI in pAF patients undergoing their first ablation did not reduce the frequency of atrial arrhythmia recurrence. This warrants further study in a prospective trial.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 14 Dec 2021; epub ahead of print

Conduction system pacing versus biventricular pacing: Reduced repolarization heterogeneity in addition to improved depolarization.

Gupta A, Pavri BB
Introduction
His-bundle pacing (HBP) and left-bundle-area pacing (LBAP) are conduction system pacing (CSP) modalities increasingly used as alternatives to conventional biventricular pacing (BiVP). While effects of CSP on ventricular depolarization have been reported, effects on ventricular repolarization have not.
Methods
QRS duration (QRSd) and validated ECG parameters of ventricular repolarization associated with arrhythmic risk (T-peak-to-T-end_Transmural , T-peak-to-T-end_Total , T-peak dispersion, QTc, QTc dispersion) were analyzed post-implant in 107 patients: 60 with CSP (HBP: n = 35, LBAP: n = 25) and 47 with BiVP. T-wave memory resolution and QTc shortening were analyzed on ECGs obtained ≥25 days post-implant. Twenty blinded measurements were obtained by both authors to assess Interobserver variability.
Results
Although QRSd was shorter with HBP versus LBAP (119 ± 7 ms vs. 132 ± 9 ms, p = .02), there were no significant differences in any repolarization parameters between these methods of CSP. However, when comparing CSP (HBP + LBAP) to BiVP, both QRSd (125 ± 5 ms vs. 147 ± 7 ms, p < .0001) and repolarization parameters (T-peak-to-T-end_Transmural : 83 ± 5 ms vs. 107 ± 8 ms; T-peak-to-T-end_Total : 110 ± 7 ms vs. 137 ± 10 ms; QTc: 470 ± 12 ms vs. 506 ± 12 ms; all p ≤ .0001) were significantly shorter with CSP. Improved T-peak-to-T-end values were unrelated to pre-implant QRSd or LV function. Interobserver variability was 4.6 ± 1.9 ms. Frontal QRS-T angle narrowing (132° to 104°, p = .001) and QTc shortening (483 ± 13 ms to 464 ± 12 ms, p = .008) were seen only with CSP.
Conclusions
In addition to improved depolarization, CSP reduced repolarization heterogeneity and provided greater T-wave memory resolution as compared to BiVP. Both modalities of CSP (HBP + LBAP) resulted in comparably reduced repolarization heterogeneity regardless of baseline QRSd and LV function. These observations may confer lower arrhythmogenic risk and warrant further study.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 14 Dec 2021; epub ahead of print

Characteristics and outcomes of ventricular tachycardia and premature ventricular contractions ablation in patients with prior mitral valve surgery.

Khalil F, Toya T, Madhavan M, Badawy M, ... Asirvatham SJ, Killu AM
Background
Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following mitral valve surgery (MVS) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves.
Objective
To investigate the characteristics, safety, and outcomes of radiofrequency CA in patients with prior MVS and ventricular arrhythmias (VA).
Methods
We identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013 and December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri-operative complications, and outcomes.
Results
In our cohort, 31 patients (77% men, mean age 62.3 ± 10.8 years, left ventricular ejection fraction 39.2 ± 13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans-septal approach in one patient. Heterogenous scar regions were present in 94% of VT patients and scar-related reentry was the dominant mechanism of VT. Forty-seven percent of PVC patients had abnormal substrate at the site targeted for ablation. Clinical VA substrates involved the peri-mitral area in six patients with VT and five patients with PVC ablation. No procedure-related complications were reported. The overall recurrence-free rate at 1-year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia-related death was documented on long-term follow-up.
Conclusion
CA of VAs can be performed safely and effectively in patients with MVS.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 14 Dec 2021; epub ahead of print

Mortality benefit of catheter ablation versus medical therapy in atrial fibrillation: An RCT only meta-analysis.

Ravi V, Poudyal A, Lin L, Larsen T, ... Sharma P, Huang HD
Introduction
Catheter ablation for atrial fibrillation (AF) in comparison to medical therapy alone is known to improve freedom from arrhythmia and quality of life, but the benefit regarding mortality is unclear. The publication of several recent large randomized controlled trials (RCT) comparing ablation with medical therapy has warranted an updated meta-analysis.
Methods
We sought to compare the effectiveness of catheter ablation versus medical therapy only in patients with AF. MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched from inception until 04/30/2021. Relevant RCTs comparing catheter ablation versus medical therapy in patients with AF were selected.
Results
A total of 24 RCTs involving 5730 adult patients were included (2992 in catheter ablation and 2738 in medical therapy). There was a reduction in all-cause mortality with catheter ablation compared with medical therapy only (risk ratio (RR) 0.70 [95% confidence interval (CI) 0.55-0.89]; p = .003). Catheter ablation also demonstrated a reduction in hospitalizations (RR 0.50 [95% CI 0.36-0.70]; p < .001), improvement in left ventricular ejection fraction (LVEF) (mean difference [MD] + 5.94% [95% CI 0.40-11.48] p = .04), greater freedom from atrial arrhythmia (RR 2.23 [95% CI 1.79-2.76]; p < .001), and AF (RR 1.95 [95% CI 1.44-2.66]; p < .001). In subgroup analysis, catheter ablation demonstrated a significant reduction in mortality and hospitalizations among patients with reduced LVEF, and when ablation was compared with antiarrhythmic drug use.
Conclusions
In comparison to medical therapy only, catheter ablation for atrial fibrillation reduces mortality, hospitalizations, and increases freedom from arrhythmia.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 14 Dec 2021; epub ahead of print

Influence of \"high\" defibrillation thresholds on patient survival and impact of system modification.

Siddiqi N, Tchou P, Niebauer MJ, Wilkoff BL, Varma N
Objective
To test whether a high defibrillation threshold (DFT) marks patients with poor outcomes which are improved when DFT is decreased by system modification (subcutaneous coil implant; SM).
Background
The electrical substrate generating fast ventricular arrhythmias may generate poor outcomes among patients treated with implantable cardioverter-defibrillators (ICDs), even when arrhythmias are treated successfully. Since patients with high DFTs have increased mortality, we contrasted survival among patients with high DFT treated with and without SM.
Methods
We studied consecutive patients undergoing ICD implantation and DFT testing at Cleveland Clinic over a 14-year period. High DFT was defined as successful defibrillation by shock strength >25 J or ≤10 J of maximal device output. Mortality was recorded using the Social Security Death Index. Survival was compared among those high DFT patients receiving SM versus the remainder.
Results
Out of 6353 patients tested, 191 (3%) had high DFT (32.1 ± 3.7 J) versus 13.9 ± 4.9 J in the remainder (\"acceptable DFT,\" p < .001). One hundred twenty-one high DFT patients (63%; 33.3 ± 3.4 J) underwent SM, which significantly decreased DFT (24.8 ± 5.9 J; p < .001). Seventy patients (37%; 30.3 ± 3.3 J) did not undergo SM. During follow-up, 38% (2363/6162; 7.8 yrs) patients with acceptable DFT died versus 48% high DFT patients (91/191; 5.6 yrs.; p < .001). Concomitantly, 48% patients with SM (58/121) died, as compared to 47% patients (33/70) without SM (p = .91); median follow-up 4.9 yrs).
Conclusion
Patients with high DFT have a higher mortality than those with acceptable DFT. The additional subcutaneous coil implant decreases DFT to an acceptable range but does not appear to improve survival. The electrical substrate underlying high DFT appears to determine survival.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 13 Dec 2021; epub ahead of print

Zero-fluoroscopy ablation in patients with cardiac electronic implantable devices.

Shimamoto K, Yamagata K, Wakamiya A, Ueda N, ... Nagase S, Kusano KF
Introduction
Utilizing a three-dimensional (3-D) mapping system and intracardiac echocardiography (ICE) has allowed ablation procedures with less or without fluoroscopy; however, there is limited data for patients with cardiac electronic implantable device (CIED) leads regarding the suspected risk of lead injury. Therefore, we sought to explore technics to perform safe trans-septal approach and catheter manipulation technique in patients with CIED leads.
Methods and results
This study comprised 49 consecutive patients (59% males, median 73 years old) with CIED who underwent catheter ablation for supraventricular tachycardia requiring the trans-septal approach, 15 without fluoroscopy (zero-fluoro group), and 34 with fluoroscopy (conventional-fluoro group), between July 2019 and April 2021. All procedures were performed under a 3-D mapping system and ICE guidance. We compared the differences in treatment and development of complications between the two groups. The procedures were for atrial fibrillation (82%) and atrial tachycardia (76%). Coronary sinus catheter insertion and the trans-septal procedure were successfully performed in all patients. The median time from venipuncture to trans-septal procedure (zero-fluoro vs. conventional-fluoro group: 28 [18-37] min vs. 24 [21-31] min, p = .70), total procedure time (231 [142-274] min vs. 175 [163-225] min, p = .63), and the acute procedural success rate (100% vs. 97%, p = 1.00) did not differ between both groups. No patient showed lead-related complications in both groups.
Conclusion
This is the first study to show zero-fluoro ablation for supraventricular arrhythmia using 3-D mapping and ICE in patients with CIED leads was feasible under careful catheter manipulation.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 17 Dec 2021; epub ahead of print

Axis deviation in nonischemic cardiomyopathy with left bundle branch block: Insights from left bundle branch pacing.

Ponnusamy SS, Vijayaraman P
Introduction
Biventricular pacing has shown excellent results in patients with heart failure and left bundle branch block (LBBB). Studies have shown that the patients with abnormal axis deviation may benefit less from cardiac resynchronization therapy (CRT) as compared to those with the normal axis. The exact reason for left axis deviation (LAD) in LBBB is not known but could be due to diseased left anterior fascicle, left ventricular enlargement, or due to advanced electrical remodeling.
Methods
The aim of the study was to analyze the incidence of LAD in nonischemic cardiomyopathy (NICM) with LBBB and the clinical outcomes following left bundle branch pacing (LBBP).
Results
We have included 64 consecutive patients with NICM and LBBB, who underwent successful LBBP. Patients were divided into two groups-Group I with baseline normal axis (n = 40; 63%) and Group II with LAD (n = 24; 37%). The mean axis changed from +23.6 ± 28.8° at baseline to +16.5 ± 35.1° and from -40.4 ± 10.3° at baseline to 7.08 ± 41.1° after LBBP in Group I and Group II, respectively. LBBP retained the normal axis in 93% of Group I patients and normalized the axis in 75% of Group II patients. The percentage changes in QRS duration, left ventricular ejection fraction, and left ventricular end-diastolic diameter were similar in both the groups (+40% vs. +32%; p = .52, +64% vs. +50%; p = 0.34, -8% vs. -6%; p = .76, respectively). Capturing the proximal LBB would correct the LAD by recruitment of left anterior fascicles and pacing proximal to the site of the septal breakthrough of the right bundle branch activation wavefront during LBBB.
Conclusion
LBBP as an alternative strategy for CRT could result in similar improvement in LBBB patients with LAD as in those with the normal axis.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 16 Dec 2021; epub ahead of print

Local impedance for the optimization of radiofrequency lesion delivery: A review of bench and clinical data.

Chu GS, Calvert P, Futyma P, Ding WY, Snowdon R, Gupta D
Introduction
Radiofrequency catheter ablation is a cornerstone of treatment for many cardiac arrhythmias. Progression in three-dimensional mapping and contact-force sensing technologies have improved our capability to achieve success, but challenges still remain.
Methods
In this article, we discuss the importance of overall circuit impedance in radiofrequency lesion formation. This is followed by a review of the literature regarding recently developed \"local impedance\" technology and its current and future potential applications and limitations, in the context of established surrogate markers currently used to infer effective ablation.
Results
We discuss the role of local impedance in assessing myocardial substrate, as well as its role in clinical studies of ablation. We also discuss safety considerations, limitations and ongoing research.
Conclusion
Local impedance is a novel tool which has the potential to tailor ablation in a manner distinct from other established metrics.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 16 Dec 2021; epub ahead of print

Ethanol ablation for ventricular arrhythmias: A systematic review and meta-analysis.

Creta A, Earley MJ, Schilling RJ, Finlay M, ... Lambiase PD, Providência R
Introduction
Ethanol ablation (EA) is an alternative option for subjects with ventricular arrhythmias (VAs) refractory to conventional medical and ablative treatment. However, data on the efficacy and safety of EA remain sparse.
Methods
A systematic literature search was conducted. The primary outcomes were 1) freedom from the targeted VA and 2) freedom from any VAs post-EA. Additional safety outcomes were also analyzed.
Results
Ten studies were selected accounting for a population of 174 patients (62.3 ± 12.5 years, 94% male) undergoing 185 procedures. The overall acute success rate of EA was 72.4% (confidence interval [CI_95% ]: 65.6-78.4). After a mean follow-up of 11.3 ± 5.5 months, the incidence of relapse of the targeted VA was 24.4% (CI_95% : 17.1-32.8), while any VAs post-EA occurred in 41.3% (CI_95% : 33.7-49.1). The overall incidence of procedural complications was 14.1% (CI_95% : 9.8-19.8), with pericardial complications and complete atrioventricular block being the most frequent. An anterograde transarterial approach was associated with a higher rate of VA recurrences and complications compared to a retrograde transvenous route; however, differences in the baseline population characteristics and in the targeted ventricular areas should be accounted.
Conclusion
EA is a valuable therapeutic option for VAs refractory to conventional treatment and can result in 1-year freedom from VA recurrence in 60%-75% of the patients. However, anatomical or technical challenges preclude acute success in almost 30% of the candidates and the rate of complication is not insignificant, highlighting the importance of well-informed patient selection. The certainty of the evidence is low, and further research is necessary.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 16 Dec 2021; epub ahead of print

Sudden unexplained death versus nonautopsied possible sudden cardiac death: Findings in relatives.

Dalgaard CV, Hansen BL, Jacobsen EM, Kjerrumgaard A, ... Christensen AH, Bundgaard H
Background
International guidelines recommend work-up of relatives to autopsy negative sudden cardiac death victims, denoted as sudden unexplained death (SUD) and nonautopsied possible sudden cardiac death (pSCD) victims. This study assesses and compare baseline characteristics and clinical outcome at initial evaluation and during follow-up of relatives to SUD and pSCD victims.
Methods
We retrospectively included data from systematic screening and routine follow-up of first-degree relatives to SUD and pSCD victims referred to our Unit for Inherited Cardiac Diseases, Copenhagen, 2005-2018. Victims with an antemortem known inherited cardiac disease were excluded.
Results
We included 371 first-degree relatives from 187 families (120 SUD, 67 pSCD): 276 SUD relatives (age 33 ± 18 years, 54% men) and 95 pSCD relatives (age 40 ± 15 years, 51% men). The diagnostic yields of inherited cardiac diseases in SUD and pSCD families were 16% and 13%, respectively (p = .8). The diagnoses in SUD families were mainly channelopathies (68%), whereas pSCD families were equally diagnosed with cardiomyopathies, channelopathies, and premature ischemic heart disease. Ninety-three percent of diagnosed families were diagnosed at initial evaluation and 7% during follow-up (5.4 ± 3.3 years). During follow-up 34% of relatives with a diagnosed inherited cardiac disease had an arrhythmic event, compared to 5% of relatives without established diagnosis (p < .0001).
Conclusions
Channelopathies dominated in SUD families whereas a broader spectrum of inherited diseases was diagnosed in pSCD families. Most affected relatives were diagnosed at initial evaluation. The event rate was low in relatives without an established diagnosis. Long-term clinical follow-up may not be warranted in all relatives with normal baseline-findings.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 15 Dec 2021; epub ahead of print

Leadless pacemaker perforations: Clinical consequences and related device and user problems.

Hauser RG, Gornick CC, Abdelhadi RH, Tang CY, ... Steele EA, Sengupta JD
Background
Cardiac perforation during leadless pacemaker implantation is more likely to require intervention than perforation by a transvenous lead. This study reports the consequences of Micra pacemaker perforations and related device and operator use problems based on information the manufacturer has submitted to the Food and Drug Administration (FDA).
Methods
FDA\'s Manufacturer and User Facility Device Experience (MAUDE) database was searched for Micra perforations. Data extracted included deaths, major adverse clinical events (MACEs), and device and/or operator use problems.
Results
Between 2016 and July 2021, 563 perforations were reported within 30 days of implant and resulted in 150 deaths (27%), 499 cardiac tamponades (89%), 64 pericardial effusions (11%), and 146 patients (26%) required emergency surgery. Half of perforations were associated with 139 (25%) device problems, 78 (14%) operator use problems, and 62 (11%) combined device and operator use problems. Inadequate electrical measurements or difficult positioning were the most frequent device problems (n = 129); non-septal implants and perforation of other structures were the most frequent operator use problems (n = 69); a combined operator use and device problem resulted in 62 delivery system perforations. No device or operator use problem was identified for 282 perforations (50%), but they were associated with 78 deaths, 245 tamponades, and 57 emergency surgeries.
Conclusion
The Micra perforations reported in MAUDE are often associated with death and major complications requiring emergency intervention. Device and use problems account for at least half of perforations. Studies are needed to identify who is at risk for a perforation and how MACE can be avoided or mitigated.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 24 Dec 2021; epub ahead of print

Economics and outcomes of sotalol in-patient dosing approaches in patients with atrial fibrillation.

Varela DL, Burnham TS, T May H, L Bair T, ... U Knowlton K, Jared Bunch T
Introduction
There exists variability in the administration of in-patient sotalol therapy for symptomatic atrial fibrillation (AF). The impact of this variability on patient in-hospital and 30-day posthospitalization costs and outcomes is not known. Also, the cost impact of intravenous sotalol, which can accelerate drug loading to therapeutic levels, is unknown.
Methods
One hundred and thirty-three AF patients admitted for oral sotalol initiation at an Intermountain Healthcare Hospital from January 2017 to December 2018 were included. Patient and dosing characteristics were described descriptively and the impact of dosing schedule was correlated with daily hospital costs/clinical outcomes during the index hospitalization and for 30 days. The Centers for Medicare and Medicaid Services reimbursement for 3-day sotalol initiation is $9263.51. Projections of cost savings were made considering a 1-day load using intravenous sotalol that costs $2500.00 to administer.
Results
The average age was 70.3 ± 12.3 years and 60.2% were male with comorbidities of hypertension (83%), diabetes (36%), and coronary artery disease (53%). The mean ejection fraction was 59.9 ± 7.8% and the median corrected QT interval was 453.7 ± 37.6 ms before sotalol dosing. No ventricular arrhythmias developed, but bradycardia (<60 bpm) was observed in 37.6% of patients. The average length of stay was 3.9 ± 4.6 (median: 2.2) days. Postdischarge outcomes and rehospitalization rates stratified by length of stay were similar. The cost per day was estimated at $2931.55 (1. $2931.55, 2. $5863.10, 3. $8794.65, 4. $11 726.20).
Conclusions
In-patient oral sotalol dosing is markedly variable and results in the potential of both cost gain and loss to a hospital. In consideration of estimated costs, there is the potential for $871.55 cost savings compared to a 2-day oral load and $3803.10 compared to a 3-day oral load.

© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 24 Dec 2021; epub ahead of print

Early arrhythmia recurrence after cryoballoon ablation in atrial fibrillation: A systematic review and meta-analysis.

Vrachatis DA, Papathanasiou KA, Kossyvakis C, Kazantzis D, ... Giannopoulos G, Deftereos S
Introduction
Early arrhythmia recurrence within the 3-month blanking period is a common event that historically has been attributed to reversible phenomena. While its mechanistic links remain obscure, accumulating evidence support the argument of shortening the blanking period. We aimed to elucidate the association between early and late arrhythmia recurrence after atrial fibrillation cryoablation.
Methods
The MEDLINE database, ClinicalTrials. gov, medRxiv, and Cochrane Library were searched for studies evaluating early and late arrhythmia recurrence rates in patients undergoing cryoablation for atrial fibrillation. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was late arrhythmia recurrence.
Results
Early arrhythmia recurrence was found predictive of decreased arrhythmia-free survival after evaluating 3975 patients with paroxysmal or persistent atrial fibrillation who underwent cryoablation (odds ratio [OR]: 5.31; 95% confidence interval [CI]: 3.75-7.51). This pattern remained unchanged after subanalyzing atrial fibrillation type (paroxysmal; OR: 7.16; 95% CI: 4.40-11.65 and persistent; OR: 7.63; 95% CI: 3.62-16.07) as well as cryoablation catheter generation (first generation; OR: 5.15, 95% CI: 2.39-11.11 and advanced generation; OR: 5.83, 95% CI: 3.68-9.23). Studies permitting antiarrhythmic drug utilization during the blanking period or examining early recurrence as a secondary outcome were found to be a significant source of statistical heterogeneity.
Conclusion
Our findings suggest that early arrhythmia recurrence is predictive of late outcomes after cryoablation for atrial fibrillation. Identifying which patients deserve earlier reintervention is an open research avenue.

© 2021 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 23 Dec 2021; epub ahead of print

The Future of Long-Term Monitoring After Catheter and Surgical Ablation for Atrial Fibrillation.

Baman JR, Passman RS
In recent years, there has been an emergence of long-term cardiac monitoring devices, particularly as they relate to non-prescribed, user-initiated, wearable- and/or smartphone-based devices. With these new available data, practitioners are challenged to interpret these data in the context of routine clinical decision-making. While there are many potential uses for long-term rhythm monitoring, in this review, we will focus on the evolving role of this technology in atrial fibrillation (AF) monitoring after catheter and/or surgical ablation. Here, we explore the landscape of prescription-based tools for long-term rhythm monitoring; investigate commercially available technologies that are accessible directly to patients, and look towards the future with investigative technologies that could have a growing role in this space. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Jan 2022; epub ahead of print

What is Different About Pulsed Field Ablation … Everything?

Haines DE
From the time of early preclinical reports of the efficacy, speed and safety of pulsed field ablation (PFA), the interventional electrophysiology community has been waiting in anxious anticipation for its clinical approval and release. As most people actively engaged in interventional electrophysiology know, PFA is the technology that creates myocardial lesions with trains of very high voltage pulses that are nanoseconds or microseconds in duration¹ . This form of ablation is nonthermal, and cell injury/death is created by electroporation of the organelles and sarcolemmal membrane, with cell death occurring via apoptosis as well as other mechanisms² .

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 09 Jan 2022; epub ahead of print

Atrial Fibrillation Ablation in Chronic Kidney Disease - Lessons from Large Datasets.

Liu CF
Outcomes data regarding atrial fibrillation (AF) treatment in chronic kidney disease (CKD) are lacking. Available data and unanswered questions in this realm will be discussed, along with how the present manuscript fits into the overall literature of this field. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 Jan 2022; epub ahead of print

Characteristics and time course of acute and chronic myocardial lesion formation after electroporation ablation in the porcine model.

Neven K, van Driel VJHM, Vink A, du Pré BC, ... Wittkampf FHM, van Es R
Introduction
Electroporation ablation creates deep and wide myocardial lesions. No data are available on time course and characteristics of acute lesion formation.
Methods
For the acute phase of myocardial lesion development, 7 pigs were investigated. Single 200J applications were delivered at 4 different epicardial right ventricular sites using a linear suction device, yielding a total of 28 lesions. Timing of applications was designed to yield lesions at 7 time points: 0, 10, 20, 30, 40, 50, 60 minutes, with 4 lesions per time point. After euthanization, lesion characteristics were histologically investigated. For the chronic phase of myocardial lesion development, tissue samples were used from previously conducted studies where tissue was obtained at 3 weeks and 3 months after electroporation ablation.
Results
Acute myocardial lesions induce a necrosis pattern with contraction band necrosis and interstitial edema, immediately present after electroporation ablation. No further histological changes such as hemorrhage or influx of inflammatory cells occurred in the first hour. After 3 weeks, the lesions consisted of sharply demarcated loose connective tissue that further developed to more fibrotic scar tissue after 3 months without additional changes. Within the scar tissue arteries and nerves were unaffected.
Conclusion
Electroporation ablation immediately induces contraction band necrosis and edema without additional tissue changes in the first hour. After 3 weeks a sharply demarked scar has been developed that remains stable during follow up of 3 months. This is highly relevant for clinical application of electroporation ablation in terms of the electrophysiological endpoint and waiting period after ablation. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 10 Jan 2022; epub ahead of print

Outcomes in Congenital and Childhood Complete Atrioventricular Block: A Meta-analysis.

Deshpande S, Shenthar J, Khanra D, Isath A, ... Kella D, Padmanabhan D
Background
The long-term outcomes of patients with congenital and childhood complete atrioventricular block (CCAVB/ CAVB) after pacemaker implantation are unclear.
Methods
We performed a meta-analysis of all the studies of CCAVB. A systematic search of PubMed and CENTRAL databases from 1^st January 1967 to 31^st January 2020 was performed. The quality of studies included was critically appraised using the Newcastle-Ottawa scale, and outcome data were analyzed using the restricted maximum likelihood function.
Results
Twenty-nine studies were eligible for analysis, with a total of 1553 patients. The all-cause-mortality was 5.7 % [95% CI: 2.5-9.9%], while PICM was seen in 3.8% [95% CI: 1.2-7.2]. Diagnosis at birth [effect size (ES)(95%CI): -2.23 (-0.36 to -0.10); p<0.001], presence of congenital heart disease ([ES(95%CI): -0.67 (0.41 to 0.93); p<0.001], younger age at pacemaker implantation ([ES(95%CI): -0.01 (-0.02 to -0.001); p=0.02], and duration of pacing [ES(95%CI): -0.03 (-0.05 to -0.003); p=0.03], were associated with an higher mortality on binominal logistic regression. None of the parameters were significant on multivariate analysis.
Conclusion
Pooled proportional mortality in patients with CCAVB and CAVB is 5.7% with an infrequent incidence of PICM (3.8%) in the paced patients with AVB suggesting that pacing in these patients is an effective management strategy with a low incidence of long-term side effects. Registry and randomized data can throw additional light regarding the natural history and appropriate management strategy in these patients. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 10 Jan 2022; epub ahead of print

Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: Insight from a porcine experimental study with 2 different LI-sensing catheters.

Matsuura G, Fukaya H, Ogawa E, Kawakami S, ... Niwano S, Ako J
Background
Local impedance (LI) can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). However, data on the effects of catheter contact angle on LI parameters are scarce. This study aimed to evaluate the influence of catheter contact angle on LI changes and lesion size with 2 different LI-sensing catheters in a porcine experimental study.
Methods
Lesions were created by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™ (STABLEPOINT). RFCA was performed with 30 watts and a duration of 30 seconds. The CF (0, 5, 10, 20, and 30 g) and catheter contact angle (30°, 45°, and 90°) were changed in each set (n=8 each). The LI rise, LI drop, and lesion size were evaluated.
Results
The LI rise increased as CF increased. There was no angular dependence with the LI rise under all CFs in the MiFi. On the other hand, the LI rise at 90° was lower than at 30° under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF increased. Regarding the difference in catheter contact angles, the LI drop at 90° was lower than that at 30° for both catheters. The maximum lesion widths and surface widths were smaller at 90° than at 30°, whereas there were no differences in lesion depths.
Conclusion
The LI drop and lesion widths at 90° were significantly smaller than those at 30°, although the lesion depths were not different among the 3 angles for the MiFi and STABLEPOINT. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 10 Jan 2022; epub ahead of print

Temporal trends and in-hospital complications of catheter ablation for atrial fibrillation among patients with moderate and advanced chronic kidney diseases: 2005-2018.

Prasitlumkum N, Chokesuwattanaskul R, Kaewput W, Thongprayoon C, ... Cheungpasitporn W, Jongnarangsin K
Introduction
Real-world data on atrial fibrillation (AF) ablation among moderate and advanced chronic kidney disease (CKD) patients have so far remained scarce, especially in-hospital AF ablation outcomes.
Methods
We drew data from the US National Inpatient Sample to identify hospitalized patients who underwent AF ablation between 2005 and 2018, and further stratified by CKD classification. We assessed the trend of AF ablation, as well as its complications.
Results
A total of 152 630 patients who were primarily hospitalized for AF and underwent ablation were estimated. Among these, CKD patients were found in a total of 1509 participants, with 978, 206, and 325 under CKD3, CKD4, and CKD5/ESKD, respectively. There was a significant increment in admission rates for AF ablation in the CKD population across all CKD classifications (p < .001). All CKD patients were statistically older, with higher coexisting comorbidities, while hypertension was found substantially lower than non-CKD patients (p ≤ .001). Importantly, CKD, especially CKD3 and CKD5/ESKD, was significantly associated with an increased risk of total complications, and total bleeding, Neurological complications were found statistically lower in CKD patients (p = .029), and no mortality rates were significantly different (p = .287).
Conclusion
Our study observed an increase in admission trends for AF ablation among moderate and advanced CKD patients from 2005 to 2018. CKD was strongly associated with higher procedure-related complications and bleeding, but neurological safety profiles and mortalities rates were nonsignificantly different.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 10 Jan 2022; epub ahead of print

Gender-specific outcomes after percutaneous left atrial appendage closure: A nationwide readmission database analysis.

Patel N, Ranka S, Hajra A, Bandyopadhyay D, ... Reddy YM, Shani J
Introduction
Thromboembolism-associated stroke is the most feared complication of atrial fibrillation (AF). Percutaneous left atrial appendage closure (pLAAC) is indicated for stroke prevention in patients with AF who can not tolerate long-term anticoagulation. We aim to study gender differences in peri-procedural and readmissions outcomes in pLAAC patients.
Methods
Using the national readmission database from January 2016 to December 2018, AF patients undergoing the pLAAC procedure were identified. We used multivariate logistic regression analyses and time-to-event Cox regression analyses to conduct the study. Propensity matching with the Greedy method was done for the accuracy of results.
Result
A total of 28 819 patients were included in our study. Among them 11 946 (41.5%) were women and 16 873 (58.6%) were men. The mean age of overall population was 76.1 ± 8.5 years, with women ~1 year older than men. The overall rate of complications was higher in women (8.6% vs. 6.6%, p < .001), primarily driven by bleeding-related complications, that is, major bleed (odds ratio [OR]: 1.32 95% confidence interval [CI]: 1.03-1.69, p = .029), blood transfusion (OR: 1.45, 95% CI: 1.06-1.97, p = .019), and cardiac tamponade (OR: 1.80, 95% CI: 1.13-2.89, p = .014). Women had two times higher peri-procedural ischemic stroke. There was no difference in peri-procedural mortality. Women remained at 20% and 13% higher risk for readmission at 30 days and 6 months of discharge.
Conclusion
Women had higher peri-procedural complications and were at higher risk of readmissions at 30 days and 6 months. However, there was no difference in mortality during the index hospitalization. Further studies are necessary to determine causality.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 11 Jan 2022; epub ahead of print

Leadless Pacemaker Implantation after Lead Extraction for Cardiac Implanted Electronic Device Infection.

Kowal J, Crossley GH
As the clinical indications for cardiac implantable electronic devices (CIED) have expanded, especially in patient populations with significant co-morbid conditions, the prevalence of CIED infections has in-creased. CIED related infections present in many forms, that may or may not lead to sepsis, ranging from isolated pocket infection to CIED endocarditis with lead involvement. The morbidity and mortality associated with CIED infection is considerable. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 Jan 2022; epub ahead of print

Leadless Pacemaker Implantation after Lead Extraction for Cardiac Implanted Electronic Device Infection.

Bicong L, Allen JC, Arps K, Al-Khatib SM, ... Thomas KL, Piccini JP
Background
Cardiac implanted electronic device (CIED) pocket and systemic infection remain common complications with traditional CIEDs and are associated with high morbidity and mortality. Leadless pacemakers may be an attractive pacing alternative for many patients following complete hardware removal for a CIED infection by eliminating surgical pocket-related complications as well as lower risk of recurrent complications.
Objective
To describe use and outcomes associated with leadless pacemaker implantation following extraction of a prior CIED system due to infection.
Methods
Patient characteristics and post-procedural outcomes were described in patients who underwent leadless pacemaker implantation at Duke University Hospital between November 11, 2014 and November 18, 2019, following CIED infection and device extraction. Outcomes of interest included procedural complications, pacemaker syndrome, need for system revision, and recurrent infection.
Results
Among 39 patients, the mean age was 71 ±17 years, 31% were women, and the most frequent primary pacing indication was complete heart block (64.1%) with 9 (23.1%) patients being pacemaker dependent at the time of Micra implantation. The primary organism implicated in the CIED infection was Staphylococcus aureus (43.6%). Nine of the 39 patients had a leadless pacemaker implanted before or on the same day as their extraction procedure, and the remaining 30 patients had a leadless pacemaker implanted after their extraction procedure. During the mean follow-up time (mean 24.8 ± 14.7 months) following the leadless pacemaker implantation, there were a total of 3 major complications: 1 groin hematoma, 1 femoral arteriovenous fistula, and 1 case of pacemaker syndrome. No patients had evidence of recurrent CIED infection after leadless pacemaker implantation.
Conclusions
Despite a prior CIED infection and an elevated risk of recurrent infection, there was no evidence of CIED infection with a mean follow up of over 2 years following leadless pacemaker implantation at or after CIED system removal. Larger studies with longer follow-up are required to determine if there is a long-term advantage to implanting a leadless pacemaker versus a traditional pacemaker following temporary pacing when needed during the peri-extraction period in patients with a prior CIED infection. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 Jan 2022; epub ahead of print

Selection and outcome of ICD and CRT-D patients - Comparison of 4384 patients from the German Device Registry to randomized controlled trials.

Köbe J, Willy K, Senges J, Hochadel M, ... Hoffmann E, Eckardt L
Background
Registry data adds important information to randomized controlled trials (RCT) on real-life aspects of implantable cardioverter-defibrillator (ICD) patients with and without cardiac resynchronization therapy (CRT-D). This analysis of the prospectively conducted German Device Registry aims at comparing mortality rates, comorbidities, complication rates to results from RCT.
Methods
The German Device registry (DEVICE) prospectively collected data on ICD and CRT-D first implantations from 50 German centres. Demographic data, details on cardiac disease, electrocardiogram (ECG), medication, and data about procedure, complications and hospital stay were stored in electronic case report forms. One year after device implantation patients were contacted for follow-up.
Results
DEVICE included n=4384 first ICD/CRT-D implantations (29.3% CRT-D devices). We found a strong adherence to guidelines with over 90% of patients being on ß-blocker and ACE-inhibitor medication and adequate QRS width in the majority of CRT-D patients. Patients receiving a CRT-D were older (67.6±11.0 years vs. 63.9±13.4 years, p<0.001) and had lower ejection fractions (mean 25% vs. 30%, p<0.001) compared to ICD patients. Dilated cardiomyopathy was the predominant underlying heart disease in CRT-D (53.3%), coronary artery disease in ICD patients (64.7%). Compared to RCT our DEVICE patients had more comorbidities (17.9% chronic kidney disease (CKD)) and higher one-year mortality rates (10.7% ICD group, 12.3% CRT group). In multivariate analysis, CKD patients had an almost 2-fold higher risk of 1-year mortality.
Conclusion
Despite relevant limitations of registry data, DEVICE highlights important differences between RCT and real-world registry data and the impact of comorbidities on mortality of ICD and CRT-D recipients. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 Jan 2022; epub ahead of print

Reaching the LVOT: You take the high road and I\'ll take the low.

Powers EM, Richardson TD
The myocardium surrounding the coronary cusps is a common site of origin for ventricular arrhythmias (VA) both idiopathic and due to cardiomyopathy. The coronary cusps may also serve as a vantage point for ablation of the left ventricular summit and sites adjacent to the proximal conduction system.^1,2 Supravalvular and infravalvular approaches to ablation in this region are commonplace and are typically utilized based on operator preference and proximity to site of earliest activation.³ While limited case series indicate that supravalvular ablation is safe and potentially effective, no data exist to assess the impact of intervening coronary cusp tissue on the biophysics of radiofrequency (RF) ablation.⁴ ventricular arrhythmias This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 Jan 2022; epub ahead of print

Conduction System Pacing Following Septal Myectomy: Insights into Site of Conduction Block.

Zheng R, Dong Y, Wu S, Su L, ... Vijayaraman P, Huang W
Introduction
Septal myectomy for obstructive hypertrophic cardiomyopathy (HCM) is associated with conduction block; however, the electrophysiological characteristics of conduction block have not been well characterized. The aim of study was to assess the feasibility and safety of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in patients with septal myectomy-associated conduction block.
Methods and results
Patients with HCM and indications for pacing or cardiac resynchronization therapy after septal myectomy were included. Electrophysiological mapping was performed to identify the site of block. The success rates and pacing characteristics of HBP and LBBAP were also recorded. The echocardiographic data and complications were documented and tracked during follow-up. Ten patients with atrioventricular block (AVB) or left bundle branch block (LBBB) post-myectomy were included in the study. The site of block was infranodal in the nine patients with AVB. HBP failed due to the lack of distal His bundle capture (N=7) or LBBB correction (N=3). LBBAP was successful in nine patients and failed in one. QRS duration narrowed from 163.3 ± 16.6 ms after surgery to 123.6 ± 15.8 ms during LBBAP (P<0.001). The mean depth of the leads was 13.3 ± 4.0 mm (range from 10 to 20 mm). At a mean follow-up of 5.3 ± 3.9 months, pacing parameters and left ventricular ejection fraction remained stable.
Conclusions
Electrophysiological mapping revealed that the site of block was infra-Hisian and not correctable with HBP in patients with HCM post-myectomy. LBBAP appears to be a more feasible physiological strategy for these patients. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 Jan 2022; epub ahead of print

Comparison of radiofrequency ablation from the coronary cusps and endocardial left ventricular outflow tract for left ventricular summit ventricular arrhythmias in a porcine and infrared thermal model.

Larsen T, Winterfield J, Ravi V, Du-Fey-de-Lavallaz JM, ... Sharma PS, Huang HD
Introduction
The coronary cusps (CCs) are utilized as an alternative vantage point for radiofrequency catheter ablation (RFCA) of left ventricular summit ventricular arrhythmias but are sometimes a challenge despite favorable activation timing and pace mapping.
Methods
Ex vivo experiments were performed in 12 intact porcine hearts submerged in a 37°C saline bath. Radiofrequency (RF) applications were delivered with an irrigated contact force sensing catheter oriented 45° to the endocardial left ventricular outflow tract (LVOT) surface and nadir of the CCs using different dosing parameters. Sections were stained in 2% triphenyltetrazolium chloride and lesion dimensions were measured. Thermal infrared imaging analysis was used to compare time-to-lethal tissue temperature and depth/area of lethal isotherms.
Results
A total of 60 RF applications were performed under different dosing parameters for (1) 30, 40, and 50  Watts (W) × 30 s and (2) 40 W × 30, 45, and 60 s. Lesion depth was greater with RFCA from LVOT than from the CCs (maximum depth 6.11 vs. 2.68 mm). Longer RF duration led to larger lesion volume in the CC group (40 W × 30 s: 8.1 ± 0.4 vs. 40 W × 60 s: 10.1 ± 0.96 mm; p = .002). One steam pop occurred in both the LVOT (50 W × 30 s) and CC groups (40 W × 60 s). Time-to-reach lethal temperature of 58°C was longer in the CC group than in the LVOT group (4.7 vs. 11.3 s; p = .02)
Conclusions:
RFCA from the CC led comparatively to shallower lesion depth than from the LVOT. Longer RF duration led to an increase in lesion volume during ablation from CCs.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 13 Jan 2022; epub ahead of print

Outcome and safety of intracardiac echocardiography guided left atrial appendage closure within zero-fluoroscopy atrial fibrillation ablation procedures.

Chen YH, Wang LG, Zhou XD, Fang Y, ... Huang WJ, Xiao FY
Background
Simultaneous atrial fibrillation (AF) catheter ablation and left atrial appendage closure (LAAC) are sometimes recommended for both rhythm control and stroke prevention. However, the advantages of intracardiac echocardiography (ICE) guidance for this combined procedure have been scarcely reported. We aim to evaluate the clinical outcomes and safety of ICE-guided LAAC within a zero-fluoroscopy catheter ablation procedure.
Methods and results
From April 2019 to April 2020, 56 patients with symptomatic AF underwent concomitant catheter ablation and LAAC. ICE with a multi-angled imaging protocol mimicking the TEE echo windows was used to guide LAAC. Successful radiofrequency catheter ablation and LAAC were achieved in all patients. Procedure-related adverse event rate was 3.6%. During the 12-month follow-up, 75.0% of patients became free of arrhythmia recurrences and oral anticoagulants were discontinued in 96.4% of patients. No ischemic stroke occurred despite two cases of device-related thrombosis versus an expected stroke rate of 4.8% based on the CHA₂ DS₂ -VASc score. The overall major bleeding events rate was 1.8%, which represented a relative reduction of 68% versus an expected bleeding rate of 5.7% based on the HAS-BLED score of the patient cohort. The incidence of iatrogenic atrial septal defect secondary to single transseptal access dropped from 57.9% at 2 months to 4.2% at 12 months TEE follow-up.
Conclusion
The combination of catheter ablation and LAAC under ICE guidance was safe and effective in AF patients with high stroke risk. ICE with our novel protocol was technically feasible for comprehensive and systematic assessment of device implantation.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 17 Jan 2022; epub ahead of print

Persistent Phrenic Nerve Palsy after Atrial Fibrillation Ablation: Follow-up Data from the Netherlands Heart Registration.

Mol D, Renskers L, Balt JC, Bhagwandien RE, ... de Jong JSSG, Netherlands Heart Registration ablation committee
Background
Persistent phrenic nerve palsy (PNP) is an established complication of atrial fibrillation (AF) ablation, especially during cryoballoon and thoracoscopic ablation. Data on persistent PNP reversibility is limited because most patients recover <24hours. This study aims to investigate persistent PNP recovery, freedom of PNP-related symptoms after AF ablation and identify baseline variables associated with the occurrence and early PNP recovery in a large nationwide registry study.
Methods
In this study, we used data from the Netherlands Heart Registration, comprising data from 9,549 catheter and thoracoscopic AF ablations performed in 2016 and 2017. PNP data was available of 7,433 procedures, and additional follow-up data were collected for patients who developed persistent PNP.
Results
Overall, mean age was 62±10 years, and 67.7% were male. Fifty-four (0.7%) patients developed persistent PNP and follow-up was available in 44 (81.5%) patients. PNP incidence was 0.07%, 0.29%, 1.41%, and 1.25% for patients treated with conventional-RF, phased-RF, cryoballoon, and thoracoscopic ablation respectively. Seventy-one percent of the patients fully recovered, and 86% were free of PNP-related symptoms after a median follow-up of 203[113-351] and 184[82-359] days, respectively. Female sex, cryoballoon, and thoracoscopic ablation were associated with a higher risk to develop PNP. Patients with PNP recovering ≤180 days had a larger left atrium volume index than those with late or no recovery.
Conclusion
After AF ablation, persistent PNP recovers in the majority of patients, and most are free of symptoms. Female patients and patients treated with cryoballoon or thoracoscopic ablation are more prone to develop PNP.
Unstructured abstract
Phrenic nerve palsy is an established atrial fibrillation (AF) ablation complication. Because phrenic nerve palsy mostly recovers within 24 hours, data on the course of persistent AF is limited. We used the Netherlands Heart Registry data to investigate the occurrence and recovery of phrenic nerve palsy in AF patients undergoing AF ablation. We analysed data from 7,433 AF ablations and found 51 patients who developed persistent phrenic nerve palsy. Follow-up data were available in 44 patients. After a median follow-up of 203 [113-351] and 184 [82-359] days, 71% of the patients fully recovered, and 86% were free of AF related symptoms. Female sex, cryoballoon, and thoracoscopic ablation were independently associated with a higher risk to develop persistent phrenic nerve palsy. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 17 Jan 2022; epub ahead of print

Patients\' and Family Members\' Views on Pacemaker Reuse: an International Survey.

Hughey AB, Muthappan P, Badin A, Baman T, ... Eagle KA, Crawford TC
Introduction
The reuse of cardiac implantable electronic devices may help increase access to these therapies in low- and middle-income countries (LMICs). No published data exist regarding the views of patients and family members in LMICs regarding this practice.
Methods and results
A paper questionnaire eliciting attitudes regarding pacemaker reuse was administered to ambulatory adult patients and patients\' family members at outpatient clinics at Centro Nacional Cardiologia in Managua, Nicaragua, Indus Hospital in Karachi, Pakistan, Hospital Carlos Andrade Marín and Hospital Eugenio Espejo in Quito, Ecuador, and American University of Beirut Medical Center in Beirut, Lebanon. There were 945 responses (Nicaragua - 100; Pakistan - 493; Ecuador - 252; Lebanon - 100). A majority of respondents agreed or strongly agreed that they would be willing to accept a reused pacemaker if risks were similar to a new device (707, 75%), if there were a higher risk of device failure compared to a new device (584, 70%), or if there were a higher risk of infection compared to a new device (458, 56%). A large majority would be willing to donate their own pacemaker at the time of their death (884, 96%) or the device of a family member (805, 93%). Respondents who were unable to afford a new device were more likely to be willing to accept a reused device (79% vs. 63%, P<0.001).
Conclusions
Patients and their family members support the concept of pacemaker reuse for patients who cannot afford new devices. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 17 Jan 2022; epub ahead of print

Wide QRS tachycardia in a young patient. What is the mechanism?

Bootla D, Jain A, Selvaraj RJ
A young patient presented with regular wide QRS tachycardia. During electrophysiology study, a wide QRS tachycardia was induced. Decremental atrial extrastimulus produced increase in AH and AV intervals with appearance of pre-excitation. What is the mechanism of tachycardia? This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 Jan 2022; epub ahead of print

Location and coupling interval of an ectopic excitation determine the initiation of atrial fibrillation from the pulmonary veins.

Kawai S, Mukai Y, Inoue S, Yakabe D, ... Chishaki A, Tsutsui H
Background:
and objective
Ectopic beats originating from the pulmonary vein (PV) trigger atrial fibrillation (AF). The purpose of this study was to clarify the electrophysiological determinant of AF initiation from the PVs.
Methods
Pacing studies were performed with a single extra stimulus mimicking an ectopic beat in the left superior pulmonary veins (LSPVs) in 62 patients undergoing AF ablation. Inducibility of AF, effective refractory period (ERP) and conduction properties within the PVs were analyzed.
Results
A single extra stimulus in LSPV induced AF in 20 patients (32% of all patients) at the mean coupling interval (CI) of 172 ms. A CI-dependent anisotropic conduction at the AF onset was visualized in a 3D-mapping. Onset of AF was site-specific with reproducibility in each individual. Mean ERP in LSPV in the AF inducible group was shorter than that in the AF non-inducible group (182 ± 55 ms vs 254 ± 51 ms, P<0.0001). LSPV ERP dispersion was greater in the AF inducible group than in the AF non-inducible group (45 ± 28 ms vs 27 ± 19 ms, P<0.01). Circumferential intra-PV conduction time (IPVCT) exhibited decremental properties in response to shortening of CI, and the prolongation of IPVCT in the AF inducible site was greater than that in the AF non-inducible site (P<0.05) in each individual.
Conclusions
Location and coupling interval of an ectopic excitation ultimately determine the initiation of AF from the PVs. ERP dispersion and circumferential conduction delay may lead to anisotropic conduction and reentry within the PVs that initiate AF. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 Jan 2022; epub ahead of print

Comparison of Ablation Index versus Time-Guided Radiofrequency Energy Dosing using Normal and Half-normal Saline Irrigation in a Porcine Left Ventricular Model.

Larsen T, Du-Fay-de-Lavallaz JM, Winterfield JR, Ravi V, ... Sharma PS, Huang HD
Background
Ablation Index (AI) is a multi-parametric quality marker to assess durability of radiofrequency (RF) lesions. The comparative effectiveness and safety of AI versus time-based energy dosing for ablation of ventricular arrhythmias is unknown.
Objective
We compared AI and time-based RF dosing strategies in left ventricles of freshly harvested porcine hearts.
Methods
Ablation was performed in vitro with an open-irrigated ablation catheter (Thermocool ST/SF), 40 Watts, CF 10-15 grams. Tissue samples were stained in triphenyltetrazolium chloride for measurement of lesion dimensions.
Results
560 lesions were performed (AI-group:[n= 360];Time-group:[n=200]). Using NS (n=280), growth in lesion depth slowed after 30 seconds and AI >550 in comparison to width, volume and magnitude of impedance drops which continued to increase with longer RF duration. Risk of steam pop (SP) was higher for RF > 30 seconds (RF<30 sec:1 SP(2.5%) vs. RF>30 sec:15 SP(25%);p=0.002) or AI targets >550 (AI 350-550:2 SP (2%) vs AI 600-750:15 SP (19%);p=0.001). Using HNS (n=280), lesion dimension and impedance drops were larger and growth in lesion depth slowed earlier (AI 500). Risk of SPs was higher above AI 550 (AI 350-550:7(7%) SPs vs. AI 600-750:28(35%) SPs; p<0.00001). While co-dependent variables, correlation between AI and time was modest-to-strong but decreased with longer RF duration.
Conclusion
In this ex-vivo study, AI was a better predictor of lesion dimensions than ablation time and magnitude of impedance drop in the LV using NS and HNS irrigation. AI targets above 550 led to higher risk of SPs. Future trials are required to verify these findings. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Jan 2022; epub ahead of print

Single Ring Isolation For Atrial Fibrillation Ablation: Impact of the Learning Curve.

Thiyagarajah A, Mahajan R, Iwai S, Gupta A, ... Lau DH, Sanders P
Introduction
Although single ring isolation is an accepted strategy for undertaking pulmonary vein (PV) and posterior wall isolation (PWI) during atrial fibrillation (AF) ablation, the learning curve associated with this technique as well as procedural and clinical success rates have not been widely reported.
Methods and results
Prospectively collected data from 250 consecutive patients undergoing de novo AF ablation using single ring isolation. PWI was achieved in 212 patients (84.8%) and PV isolation without PWI was achieved in 37 patients (14.4%). Thirty-one cases (12.4%) demonstrated inferior line sparing where PWI was achieved without a continuous posterior wall inferior line. A learning curve was observed, with higher rates of PWI (98% last 50 versus 82% first 50 cases, p=0.016), higher rates of inferior line sparing (20% last 50 versus 8% first 50 cases, p=0.071) and lower ablation times (43.8 minutes (IQR:34.6-57.0 minutes) last 50 versus 96.5 minutes (IQR:80.8-115.8 minutes) first 50 cases; p<0.001). Three (1.3%) major procedure-related complications were observed. Twelve-month, single-procedure freedom from atrial arrhythmia without drugs was 70.5% (95%CI:61.5-77.7%) and 60.0% (95%CI:50.2-68.4%) for paroxysmal and persistent/longstanding persistent AF. Twelve-month multi-procedure freedom from atrial arrhythmia was 92.2% (95%CI:85.6-95.9%) and 85.6% (95%CI:77.2-91.0%) for paroxysmal and persistent/longstanding persistent AF.
Conclusion
Employing a single ring isolation approach, PWI can be achieved in most cases. There is a substantial learning curve with higher rates of PWI, reduced ablation times, and higher rates of inferior line sparing as procedural experience grows. Long-term freedom from arrhythmia is comparable to other AF ablation techniques. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 24 Jan 2022; epub ahead of print

Late Gadolinium Enhancement Cardiac Magnetic Resonance Imaging of Ablation Lesions after Post-Infarction Ventricular Tachycardia Ablation:Implications for VT Recurrence.

Ghannam M, Liang J, Attili A, Cochet H, ... Morady F, Bogun F
Background
Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging distinguishes between intrinsic post-infarction scar and radiofrequency ablation lesion related scar (dark core lesions (DCLs)) in patients with prior ventricular tachycardia (VT) ablation procedures.
Objective
To combine LGE-CMR and electroanatomic mapping data to describe the relationship between DCLs and recurrent VT among patients undergoing repeat ablations for post-infarction VT.
Methods
Consecutive patients with repeat ablation for post-infarct VT with LGE-CMR prior to the repeat procedures were studied. Prior ablation procedures and implantable cardiac defibrillator electrograms were analyzed to determine new versus previously documented VT. DCLs were identified on pre-procedure LGE-CMR and registered to electroanatomic maps. A control group of patients undergoing repeat ablation procedures without imaging was included.
Results
Nineteen study patients and 14 control patients were followed for 2.6[1.6-5.6] years (31(94%) men, age 65.8±8.4 years, ejection fraction 24.7±10.3, P>0.10 for all). DCLs corresponded to unexcitable tissue during repeat procedures (area 22.4±15.1 vs 22.9±16.8 cm³ , correlation coefficient =0.93). Most VT target sites [39/50(78%)] were in close proximity (<1cm) to DCLs. Most DCL related VTs 32/39 (82%) were new VTs. Patients with LGE-CMR imaging incorporated into their ablation procedures had improved 24-month survival from VT (64% vs 38%, log rank P<0.02).
Conclusion
LGE-MRI can identify prior ablation lesions corresponding to non-excitable tissue during repeat ablation procedures for post-infarction VT. VT target sites are often located in close proximity to the DCL area that may function as a fixed border for reentry circuits. Registration of DCL from prior ablation may facilitate repeat ablation procedures. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 Jan 2022; epub ahead of print

Device-related Infection Associated with Increased Mortality Risk In De Novo Transvenous Implantable Cardioverter-Defibrillator Medicare Patients.

El-Chami MF, Liu Y, Griffiths RI, Knight BP, ... Jacobsen CM, Baddour LM
Introduction
Transvenous implantable cardioverter-defibrillators (TV-ICD) infection is a serious complication that frequently requires complete device removal for attempted cure, which can be associated with patient morbidity and mortality. The objective of this study is to assess mortality risk associated with TV-ICD infection in a large Medicare population with de novo TV-ICD implants.
Methods
A survival analysis was conducted using 100% fee-for-service Medicare facility-level claims data to identify patients who underwent de novo TV-ICD implantation between 7/2016 and 1/2018. TV-ICD infection within 2 years of implantation was identified using ICD-10 and CPT codes. Baseline patient risk factors associated with mortality were identified using the Charlson Comorbidity Index categories. Infection was treated as a time-dependent variable in a multivariate Cox proportional hazards model to account for immortal time bias.
Results
Among 26,742 Medicare patients with de novo TV-ICD, 518 (1.9%) had a device-related infection. The overall number of decedents was 4,721 (17.7%) over 2 years, with 4,555 (17%) in the non-infection group and 166 (32%) in the infection group. After adjusting for baseline patient demographic characteristics and various comorbidities, the presence of TV-ICD infection was associated with an increase of 2.4 [95% CI: 2.08-2.85] times in the mortality hazard ratio.
Conclusion
The rate of TV-ICD infection and associated mortality in a large, real-world Medicare population is noteworthy. The positive association between device-related infection and risk of mortality further highlights the need to reduce infections This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 Jan 2022; epub ahead of print

Steroid Use for Recovery of advanced atrioVentricular block Immediately after VALvular surgery (SURVIVAL): a preliminary randomized clinical trial.

Ghodsi S, Masoudkabir F, Hosseini Z, Davarpasand T, ... Bagheri J, Hasanzadeh H
Background
Atrioventricular block (AVB) is an important complication following valvular surgery. Several factors including inflammation-mediated injury might trigger AVB.
Methods
Patients with advanced postoperative AVB were randomly assigned to receive either dexamethasone (0.4 mg /kg, maximum 30 mg /day) intravenously for three days or conservative care only. Primary endpoint was recovery rate in day five since randomization. Secondary endpoints were recovery rate in day 7 and day 10, cumulative AVB time, PPM implantation rate, length of stay in critical care units, and post-operative major adverse events (MAE).
Results
We enrolled 139 subjects (48.9% male) with mean age of 59.9 years randomly allocated to intervention group (n= 69) and control group (n= 70). Dexamethasone led to higher recovery rates at day 5 (82.6% vs. 62.9%, P= 0.009) and day 7 (88.4% vs. 61.4%, P< 0.0001) respectively. This benefit ceased at day 10 (83.05 vs 78.6 %, P=0.547). Median cumulative AVB time was shorter in dexamethasone group compared to control group (41 hours vs 64 hours, P = 0.044). PPM implantation rates were similar between the dexamethasone and control groups (15.9% vs 17.1 %, respectively, P=0.849). Median length of stay in ICU (10 days vs 12 days, P= 0.03) and MAE (17.4 % vs 25.7%, P=0.133) tended to be lower with dexamethasone.
Conclusion
Dexamethasone may serve as a safe and effective medication to help hasten recovery of advanced AVB after valvular surgery. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 Jan 2022; epub ahead of print

Association between Left Atrial Appendage Fibrosis and Thrombus Formation: A Histological Approach.

Miyauchi S, Tokuyama T, Uotani Y, Miyamoto S, ... Takahashi S, Nakano Y
Introduction
Although recent echocardiographic studies have suggested that left atrial appendage (LAA) remodeling contributes to the development of LAA thrombus (LAAT), histological evidence is absent. The objective of this study was to examine clinical parameters and histological findings to clarify the factors involved in LAAT formation.
Methods
A total of 64 patients (no atrial fibrillation [AF], N = 22; paroxysmal AF, N = 16; non-paroxysmal AF, N = 26) who underwent LAA excision during surgery were enrolled. Transthoracic and transesophageal echocardiography were performed before surgery. We evaluated the fibrosis burden (%) in the excised LAA sections with Azan-Mallory staining in patients with a LAAT compared with those without.
Results
Patients with paroxysmal and non-paroxysmal AF had a higher LAA fibrosis burden than those without AF (P = 0.005 and P < 0.0001, respectively). Among the patients enrolled, 16 had a LAAT and 15 of them had non-paroxysmal AF. Among the non-paroxysmal AF patients, those with a LAAT had significantly higher LAA fibrosis burden than those without (23.8% [14.8%-40.3%] vs. 12.8% [7.4%-18.2%], P = 0.004) and echocardiographic parameters of the left atrial volume index (R = 0.543, P = 0.01), LAA depth (R = 0.452, P = 0.02), and LAA flow velocity (R = -0.487, P = 0.01) were correlated with the LAA fibrosis burden.
Conclusion
This study provided histological evidence that LAA fibrosis is related to LAAT formation. Echocardiographic parameters of LAA remodeling and function were correlated with the LAA fibrosis burden. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 Jan 2022; epub ahead of print

Pulmonary vein isolation using Cryoballoon ablation versus RF ablation using ablation index following the CLOSE protocol: a Prospective Randomized Trial.

Theis C, Kaiser B, Kaesemann P, Hui F, ... Bekeredjian R, Huber C
Background
The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 80 and 90 %. This prospective, randomized study investigated the efficacy of Cryoballoon PVI (CBA) versus pulmonary vein isolation with RF-energy following the CLOSE protocol (ablation index (AI), interlesion distance ≤ 6 mm, surround flow catheter) in terms of single-procedure arrhythmia-free outcome and safety.
Methods and results
A total number of 150 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group-A patients, PVI was performed with the 23 or 28 mm Cryoballoon (Artic Front^TM Balloon in conjunction with an Achieve Mapping Catheter, Medtronic Inc). The ablation procedure in group B was performed with RF-energy, using AI and following the CLOSE protocol. PVI using AI incorporates stability, contact force (CF), time and power. The CLOSE protocol combines AI and ≤ 6 mm interlesion distance using a surround flow catheter (Biosense Webster Thermocool STSF). A total of 75 patients were randomized into each group without significant differences in baseline characteristics. During a mean follow-up of 12 ± 4.5 months after a single procedure, 64 (85.33 %) patients of group A were free of arrhythmia recurrence versus 65 (86.67 %) patients in group B (p=ns). A total of 14 patients (group A: 7 (9.33 %) group B: 7 (9.33 %); p=ns) underwent a redo-procedure. No significant difference between both groups was observed in terms of PV recovery (group A: 4 (5.33 %) vs. group B: 3 (4 %); p=ns). In 2 patients of group A and 4 patients of group B the PVs were durably isolated, whereas the patients had AF recurrence caused by extra-PV AF sources. Two patients of each group had continued paroxysmal AF but did not undergo redo-procedure. Patients of group A showed significantly more AF recurrence during the blanking period of three months (group A: 14 (18.67 %) versus group B: 6 (8 %); p<0.05. With regard to the procedural data, the procedure time was significantly shorter in group A (70.53 ± 16.13 versus 115.35 ± 15.38; p<0.01), the flouroscopy time and dose area product showed no significant differences (table 2). Both procedures were performed with a low number of complications, no pericardial effusion was seen in either group, in group A two patients had a significant hematoma of the groin with the need of surgical repair.
Conclusions
Cryoballoon PVI and PVI using ablation index following the CLOSE protocol are equally efficient in achieving durable PV-isolation. In this study, Cryoballoon ablation led to significantly more AF recurrence during the blanking period. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 Jan 2022; epub ahead of print

Split Accessory Pathway Potentials in a Patient with Antidromic AVRT.

Liu W, Gu W, Luo X, Li J, Xiong N
A 27-year-old female presenting with palpitation underwent electrophysiology study, who had mild preexcitation in surface ECG. An accessory pathway with weak anterograde conduction was found. During isoproterenol infusion, the delta wave promptly became prominent, an antidromic AV reentrant tachycardia was then induced. When the pathway was mapped, widely split double pathway potentials were observed at 12 o\'clock site of tricuspid annulus during mild preexcitation, demonstrating an example of intra-pathway conduction delay. Ablation at the site caused accelerated pathway rhythm and eliminated the pathway, rendering the tachycardia non-inducible. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 20 Jan 2022; epub ahead of print