Multielectrode Catheter-Based Pulsed Field Ablation of Persistent and Long-Standing Persistent Atrial Fibrillation

Abstract Background and Aims Rhythm control of non-paroxysmal atrial fibrillation (AF) is significantly more challenging, as a result of arrhythmia perpetuation promoting atrial substrate changes and AF maintenance. We describe a tailored ablation strategy targeting multiple left atrial (LA) sites via a pentaspline pulsed field ablation (PFA) catheter in persistent AF sustained beyond 6 months (PerAF6m) and long-standing persistent AF (LSPAF). Methods The ablation protocol included the following stages: pulmonary vein antral and posterior wall isolation plus anterior roof line ablation (Stage 1); electrogram-guided substrate ablation (Stage 2); atrial tachyarrhythmia regionalization and ablation (Stage 3). Results Seventy-two age:68±10years, 61.1%males; AF history: 25 (18-45) months patients with PerAF6m (52.8%) and LSPAF (47.2%) underwent their first PFA via the FarapulseTM system. LA substrate ablation (Stage 1 and 2) led to AF termination in 95.8% of patients. AF organized into a left-sided atrial flutter (AFlu) in 46 (74.2%) patients. The PFA catheter was used to identify LA sites showing diastolic, low-voltage electrograms and entrainment from its splines was performed to confirm the pacing site was inside the AFlu circuit. Left AFlu termination was achieved in all cases via PFA delivery. Total procedural and LA dwell times were 112±25min and 59±22 min, respectively. Major complications occurred in 2 (2.8%) patients. Single-procedure success rate was 74.6% after 14.9±2.7 months of follow-up; AF-free survival was 89.2%. Conclusions In our cohort, PFA-based AF substrate ablation led to AF termination in 95.8% of cases. Very favorable clinical outcomes were observed during 1year of follow-up.