Posterior Inter-Antral Linear Ablation Using Pulsed Field Energy: Electrophysiological Validation and Early Clinical Outcomes

INTRODUCTION: Durable conduction block across the left atrial roof remains challenging because of complex anatomy and limitations of thermal energy delivery. Pulsed field ablation (PFA) may enable a short posterior inter-antral line as an adjunctive strategy beyond pulmonary vein isolation (PVI), providing linear conduction block at a more inferior posterior LA location than a conventional roofline. However, its electrophysiological characteristics and clinical relevance remain uncertain. METHODS AND RESULTS: In this single-center, nonrandomized comparative cohort study, a prospectively enrolled cohort undergoing PVI plus posterior inter-antral linear ablation was compared with contemporaneous patients undergoing PVI without additional left atrial ablation. The primary clinical endpoint was atrial arrhythmia recurrence beyond a 90-day blanking period. Propensity score matching was the primary comparative analysis; inverse probability of treatment weighting and multivariable Cox regression were sensitivity analyses. Among 306 patients, 65 underwent posterior inter-antral linear ablation and 241 underwent PVI alone. Posterior-line ablation produced characteristic reciprocal pacing responses and a caudal-to-cranial posterior wall activation pattern consistent with conduction block. During a median follow-up of 198 days, atrial arrhythmia recurrence occurred in 4 of 65 (6.2%) versus 38 of 241 (15.8%) patients. In the primary PSM analysis, posterior inter-antral linear ablation was associated with lower recurrence (HR 0.23; 95% CI 0.07-0.78), with consistent results in sensitivity analyses. CONCLUSION: Posterior inter-antral linear ablation using PFA provides a reproducible electrophysiological pattern of conduction block and was associated with lower short-term atrial arrhythmia recurrence than PVI alone in patients with paroxysmal atrial fibrillation. These findings warrant confirmation in randomized trials.