EP Edge Journal Watch: Cardiac Electrophysiology Research

In this EP Edge and Heart Rhythm Society collaborative podcast, Dr. Niraj Sharma and Dr. Mike Lloyd examine new evidence challenging several long-standing assumptions in cardiac electrophysiology: when to choose catheter ablation over antiarrhythmic drug therapy for atrial fibrillation, whether left bundle branch area pacing should replace conventional right ventricular pacing in patients who require substantial ventricular pacing, and how broadly the lessons of CAST should continue to restrict flecainide and other Class Ic antiarrhythmic drugs.
The atrial fibrillation discussion brings together two complementary 2026 Heart Rhythm meta-analyses. Demy L. Idema and colleagues evaluated antiarrhythmic drugs versus catheter ablation for rhythm control across randomized controlled trials, focusing on AF recurrence, hospitalization, mortality, and treatment-related complications. Marwan Shawki and colleagues examined the safety of catheter ablation versus antiarrhythmic drugs across 24 randomized trials involving 6,665 participants. Together, the studies raise an important contemporary question: as ablation becomes more effective and procedural safety improves, does antiarrhythmic drug therapy still deserve an automatic position ahead of ablation in the AF treatment pathway?
The discussion then turns to physiologic pacing and the PACE-HF trial by Jenish P. Shroff and colleagues, published in the European Heart Journal. In this prospective randomized trial, left bundle branch area pacing was compared with conventional right ventricular pacing in patients with preserved or mildly reduced left ventricular ejection fraction who were expected to require substantial ventricular pacing. The trial provides randomized evidence on ventricular function, pacing burden, heart failure hospitalization, and the potential consequences of chronic nonphysiologic right ventricular activation.
Finally, the podcast revisits flecainide more than three decades after the Cardiac Arrhythmia Suppression Trial (CAST). The discussion incorporates the systematic review by Li and colleagues in Heart Rhythm examining how CAST reshaped flecainide research and clinical use, together with the nationwide cohort study by T.-C. Huang and colleagues in Heart Rhythm evaluating Class Ic antiarrhythmic therapy after PCI in patients with new-onset atrial fibrillation. The central question is not whether CAST was correct in the post-myocardial-infarction population it studied, but whether its findings have been extrapolated too broadly to contemporary patients with stable or revascularized coronary disease, preserved ventricular function, and atrial rather than ventricular arrhythmias.
Across atrial fibrillation ablation, conduction-system pacing, and Class Ic antiarrhythmic therapy, the episode asks a common question: when new evidence challenges an established electrophysiology default, when is the evidence strong enough to change everyday practice?
Studies Discussed
Idema DL, et al. Antiarrhythmic drugs vs catheter ablation as rhythm control for atrial fibrillation: A systematic review and meta-analysis of randomized controlled trials. Heart Rhythm. 2026;23:1465-1475.
Shawki M, et al. Safety of catheter ablation compared with antiarrhythmic drugs for atrial fibrillation: A systematic review and meta-analysis of randomized trials. Heart Rhythm. 2026;23:1453-1464.
Shroff JP, et al. Left bundle branch area pacing vs right ventricular pacing in preserved or mildly reduced ejection fraction: the PACE-HF trial. European Heart Journal. 2026;47:3298-3300.
Li et al. Flecainide use before and after the Cardiac Arrhythmia Suppression Trial: A systematic review. Heart Rhythm. 2026.
Huang TC, et al. Class Ic antiarrhythmic therapy after PCI in new-onset atrial fibrillation: Safety and clinical outcomes from a nationwide cohort. Heart Rhythm. 2026;23:e1372-e1382.

What can nine carefully selected studies teach us about the changing practice of cardiac electrophysiology?
In EP Edge® Journal Watch Issue 34, August 2026, Dr. Sharma provides a clinically focused review of emerging evidence across atrial fibrillation, pulsed field ablation, implantable cardiac devices, sudden death prevention, resuscitation, occupational radiation safety, and postural orthostatic tachycardia syndrome.
This episode examines whether transvenous and subcutaneous ICD shocks produce different patterns of myocardial injury; the incidence and clinical meaning of migraine following pulsed field ablation; whether routine mechanical CPR improves meaningful survival after out-of-hospital cardiac arrest; and why hemolysis and renal effects may differ among PFA platforms and workflows.
Dr. Sharma also explores the FINE-HEART analysis of finerenone and sudden death, the LOSE-AF randomized trial of weight loss in older patients with persistent atrial fibrillation, occupational radiation exposure during pregnancy, the prognostic significance of skin thickness over cardiac implantable electronic devices, and a randomized crossover comparison of ivabradine and propranolol for POTS.
Rather than simply reciting percentages and P values, the discussion explains why each study was undertaken, how it was designed, what its principal statistical findings mean, where uncertainty remains, and how the results might—or might not—affect clinical practice. Each analysis concludes with the EP Edge take: a practical interpretation for physicians, trainees, nurses, allied professionals, and others caring for patients with heart-rhythm disorders.
The episode also previews the early September 2026 arrival of EPEdge.org and the EP Edge app. Built around Knowledge · Access · Humanity, the new platform will bring together EP Edge Analytics, EP Edge Academy, CME and MOC opportunities, EP Edge Rx, practical clinical resources, and the complete EP Edge newsletter archive.
And don’t miss next week’s must-listen collaborative issue with the Heart Rhythm Society.
READ AND SUBSCRIBE
EP Edge Journal Watch on LinkedIn:
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EP Edge Newsletter on LinkedIn:
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EP Edge on Substack:
https://epedge.substack.com
EPEdge.org—launching in early September 2026:
https://epedge.org

How long should anticoagulation continue after an apparently successful atrial fibrillation ablation? Should prophylactic pulmonary vein isolation be added during typical atrial flutter ablation in patients with heart failure? What do emerging data reveal about neurologic events, hemolysis, and renal safety with pulsed-field ablation?
In EP Edge® Journal Watch Issue 33, August 2026, Dr. Sharma provides a clinically focused and thought-provoking review of nine important cardiac electrophysiology studies published in Heart Rhythm and JACC: Clinical Electrophysiology.
This episode examines:
 The proposed 8.1-month timing for oral anticoagulant discontinuation after successful AF ablation 
 Prophylactic pulmonary vein isolation in patients with typical atrial flutter and heart failure 
 Lesion delivery, irrigation rates, and neurovascular events with pulsed-field ablation 
 PFA-associated hemolysis, acute kidney injury, and platform-specific renal safety 
 Transvenous lead extraction outcomes in patients with prior sternotomy 
 First-in-human vibration-based lead extraction 
 The line-of-block pacing maneuver for distinguishing AV nodal from accessory pathway conduction 
 The SCAAF-ERS electrocardiographic score for sudden cardiac arrest risk in atrial fibrillation 
 A gain-of-function KCNJ8 variant linked with inherited and acquired J-wave syndromes 
Rather than simply listing study results, Dr. Sharma explains why each investigation was needed, what clinical uncertainty it attempted to resolve, how the methodology affects interpretation, and what the principal statistics mean in practical terms. Each paper concludes with the EP Edge Take, including the potential implications for current practice, the limitations that should temper interpretation, and the questions that future research must answer.
The episode also includes updates on the EP Edge® app, the new epedge.org website, and the upcoming EP Edge® Journal Watch collaboration with the Heart Rhythm Society.
Full references, study graphics, and the complete written analysis are available through the EP Edge® Journal Watch newsletter on LinkedIn and on Substack at epedge.substack.com.
Questions, suggestions, or concerns can be sent to epedge.cast@gmail.com.

Can anticoagulation be safely discontinued after successful atrial fibrillation ablation? Is the traditional prohibition against flecainide in structural heart disease too broad or does CAST remain an essential warning? And can AI-enabled ECGs, unipolar voltage mapping, and cardiac MRI improve how we detect AF and characterize arrhythmic substrate?
In EP Edge® Journal Watch Issue 32, Dr. Niraj Sharma examines important electrophysiology research published in Heart Rhythm and JACC: Clinical Electrophysiology, translating the methodology, statistical findings, limitations, and clinical implications into practical insights for electrophysiologists and cardiovascular clinicians.
Topics include:
Discontinuing oral anticoagulation after AF ablation
The clinical and economic consequences of delayed AF ablation
Estimating AF burden after several AF-free monitoring days
Multicenter validation of an AI-enabled ECG model for predicting AF
Unipolar voltage mapping and lesion durability after pulsed field ablation
High-density electroanatomic mapping versus cardiac MRI in nonischemic cardiomyopathy
How CAST changed the direction of flecainide research
Class Ic antiarrhythmic therapy after PCI
Reconsidering flecainide in selected structural heart disease phenotypes
Amiodarone-associated thyrotoxicosis in patients with pre-existing hypothyroidism
The episode separates statistical association from causal evidence and asks what these findings should and should not change in current practice. It also outlines the prospective trials needed to determine whether anticoagulation withdrawal, AI-guided AF screening, voltage-guided PFA, and phenotype-based flecainide prescribing can improve clinically meaningful outcomes.
Dr. Sharma also previews the next collaborative EP Edge® Journal Watch issue with the Heart Rhythm Society, the forthcoming EP Edge® app, and the new epedge.org platform—bringing podcasts, newsletters, EP Edge Rx, EP Edge Academy, and additional clinical and patient-focused resources into one accessible ecosystem.
References, graphics, and the complete written analysis are available through EP Edge® Journal Watch on LinkedIn and Substack:
https://epedge.substack.com
Questions, suggestions, or concerns: epedge.cast@gmail.com

In EP Edge® Journal Watch Issue 31, August 2026, Dr. Sharma examine new evidence that challenges several familiar assumptions in cardiac electrophysiology.
Should patients with atrial fibrillation routinely stop drinking coffee? An American Heart Association scientific statement reviews the cardiovascular effects of caffeine, including randomized evidence showing a 39% lower risk of recurrent AF among habitual coffee drinkers who continued coffee after cardioversion. The discussion separates ordinary coffee consumption from energy drinks and concentrated caffeine while considering premature ventricular contractions, blood pressure, sleep, and individualized patient counseling.
The episode also investigates whether wine adds cardiovascular benefit to the Mediterranean diet. The apparent benefit weakened when moderate drinkers were compared with very-light drinkers, demonstrating how the reference group can change the statistical narrative. Importantly, these studies did not evaluate AF outcomes and do not support prescribing wine as cardiovascular therapy.
Other studies covered include:
• Pulsed-field ablation for persistent AF, with pooled one-year freedom from atrial arrhythmia of 72.3%, but no proven superiority over thermal ablation.
• Broad and predominantly left-sided pulmonary vein reconnection patterns during redo procedures after pentaspline pulsed-field ablation.
• Real-world Sphere-9 safety reports involving ventricular arrhythmias, implanted-device interactions, stroke, AV block, and other signals, interpreted in the absence of a procedural denominator.
• The SMARTBEATS randomized trial of smartphone rhythm monitoring before cardioversion, which prevented approximately one same-day cancellation for every six patients monitored.
• Autopsy-based sudden cardiac death research showing that myocardial infarction accounted for 41% of confirmed sudden cardiac deaths and highlighting the limitations of ejection fraction alone.
• End-tidal carbon dioxide trajectories during out-of-hospital cardiac arrest and why no single value should become a stand-alone termination rule.
• Atrial fibrillation, bradycardia, conduction disease, and ventricular ectopy in masters athletes, reinforcing that exceptional fitness does not provide immunity from clinically important arrhythmias.
Listen for the study rationale, methodology, clinically meaningful statistics, limitations, and the EP Edge take on how these findings may influence practice.
Complete references, graphics, and detailed analysis are available through the LinkedIn newsletter EP Edge® Journal Watch and at epedge.substack.com.