Introduction: Pulsed field ablation (PFA) is a novel nonthermal ablation approach using rapid electrical pulses to cause cardiac cell apoptosis via electroporation. Our study aims to investigate the feasibility and safety of PFA for persistent atrial fibrillation (PeAF). Methods: 32 consecutive patients diagnosed with PeAF were enrolled in our study. All patients underwent PFA treatment using the strategy including pulmonary vein isolation (PVI), left atrial posterior wall (LAPW) isolation, cavotricuspid isthmus (CTI) block, and mitral isthmus (MI) block. Acute and follow-up procedure outcomes were evaluated, and adverse events related to the ablation procedure were also observed. Results: One-year survival free from atrial tachyarrhythmia post-ablation was 65.6%. Acute success rates for PVI, LAPW isolation, CTI block, and MI block were 100%, 100%, 96.9%, and 81.3%, respectively. Eleven cases (34.4%) experienced atrial tachyarrhythmia recurrence, with 8 cases being atrial fibrillation recurrence and 3 cases being atrial flutter recurrence. Three patients underwent repeat ablation. Minor complications were encountered in 4 patients with asymptomatic cerebral lesions. Vagal responses were commonly observed during the procedure. No severe coronary vasospasm or severe haemolysis occurred in our cohort. Conclusion: PFA with the strategy including PVI, LAPW isolation, CTI block, and MI block is feasible, safe, and associated with a high rate of freedom from atrial tachyarrhythmia recurrence at 1 year in patients with PeAF.

Abstract Introduction: Linear ablation in addition to pulmonary vein antrum isolation (PVAI) has failed to improve the success rate for persistent atrial fibrillation (PeAF), due to incomplete block of ablation lines, especially in the mitral isthmus (MI). Methods and results: The study enrolled 191 patients (66 in group 1 and 125 in group 2). In group 1, EI-VOM was firstly performed, followed by radiofrequency (RF) applications targeting bilateral PVAI and bidirectional block in the roofline, cavotricuspid isthmus, and MI. In group 2, PVAI and the three linear ablations were completed using only RF energy. MI block was achieved in 63(95.5%) and 101(80.8%) patients in group 1 and 2, respectively (p=0.006). Patients in group 1 had shorter ablation time for left pulmonary vein antrum (8.15 min vs 12.59 min, p<0.001) and MI (7.0 min vs 11.8 min, p<0.001) and required less cardioversion (50(78.5%) vs 113(90.4%), p=0.007). During the 12-month follow-up, 58 (87.9%) patients were free from AF/AT in group 1 compared with 81 (64.8%) in group 2 (p<0.001). In multivariate cox regression, the ‘upgraded 2C3L’ procedure is associated with a lower recurrence rate (HR 0.27, 95%CI 0.12-0.59). Conclusion: Compared with the conventional ‘2C3L’ approach, the ‘upgraded 2C3L’ approach has higher effectiveness for ablation of PeAF.