EP Edge Journal Watch, Issue 27, June 2026: CT-Guided VT Ablation, PFA Safety, Posterior Wall Isolation, and AF Substrate Precision

In this episode of EP Edge® Journal Watch, Dr. Sharma reviews the June 2026 Issue 27 newsletter, focusing on a central question in modern cardiac electrophysiology: how do we better match mechanism to intervention? This issue explores smarter procedural targeting, safer energy delivery, functional substrate assessment, and the evolving biology of atrial and ventricular arrhythmias.The episode begins with the InEurHeart trial, a randomized study of CT-guided ventricular tachycardia ablation in ischemic cardiomyopathy. Dr. Sharma explains why preprocedural cardiac CT may help identify scar-related VT isthmuses, shorten procedure time, and create a more reproducible workflow, while also discussing why anatomy alone cannot fully replace functional electroanatomic mapping.The discussion then moves to posterior wall isolation in persistent atrial fibrillation, including a study of very high-output pace-capture testing. The key clinical question is whether more aggressive confirmation of posterior wall inexcitability improves outcomes. The results challenge the assumption that more lesions, more energy, and stricter capture endpoints necessarily produce better rhythm control.Next, the episode examines CTI DEEP mapping, or decrement evoked potentials, as a functional electrophysiology marker for atrial flutter susceptibility in patients undergoing AF ablation. Dr. Sharma explains what DEEP is, how it is measured using extrastimulus pacing from the lateral tricuspid annulus and proximal coronary sinus, and why functional conduction delay may be more informative than CTI anatomy alone.The procedural safety conversation continues with a mechanistic study of left bundle branch area pacing showing that sheath withdrawal may be a vulnerable phase for septal perforation. This section highlights why a pacing lead that appears stable after deployment may still be mechanically vulnerable during early sheath withdrawal, especially in constrained right atrial anatomy.The episode then turns to pulsed field ablation safety, reviewing the HEMO-PFA study and a renal biomarker study after PFA. These papers explore hemolysis, myocardial injury, acute kidney injury, application burden, delayed creatinine changes, and why PFA safety should be considered patient-specific, lesion-set-specific, and system-specific rather than generic.In the atrial fibrillation substrate section, Dr. Sharma reviews the VISION Cardiac Surgery cohort on postoperative atrial fibrillation and its association with recurrent clinical AF, mortality, and heterogeneous stroke risk. The episode also reviews a state-of-the-art paper on inflammatory pathways in AF, including cytokines, NLRP3 inflammasome activation, oxidative stress, autonomic imbalance, epicardial adipose tissue, fibrosis, ion-channel remodeling, and why risk-factor modification should be viewed as substrate therapy.The final section covers modifiable exposure risk, including an experimental study of vaping coolants and ventricular arrhythmogenicity, followed by a nuanced discussion of alcohol intake and incident atrial fibrillation. Dr. Sharma emphasizes that the alcohol meta-analysis does not prove alcohol prevents AF; rather, it shows a nonlinear observational association, with very high intake clearly associated with increased AF risk.This episode is designed for electrophysiologists, cardiologists, EP fellows, advanced practice providers, cardiovascular researchers, and clinicians interested in atrial fibrillation, ventricular tachycardia, catheter ablation, pulsed field ablation, physiologic pacing, arrhythmia mechanisms, and evidence-based EP practice.For full references, figures, graphics, and detailed statistical interpretation, visit the EP Edge Journal Watch newsletter on LinkedIn and Substack at epedge.substack.com. Questions, suggestions, or concerns can be sent to epedge.cast@gmail.com.