Repeat pulmonary vein isolation and anterior line ablation using a novel point-by-point pulsed-field ablation system

BACKGROUND:Pulsed field ablation (PFA) is a nonthermal energy source for ablation of cardiac arrhythmias. This study investigated the prospective outcomes of a novel PFA generator in conjunction with a commercially available, contact force-sensing, focal ablation catheter. OBJECTIVE:We sought to assess the feasibility, safety, and lesion characteristics of point-by-point PFA in consecutive patients undergoing repeat ablation of atrial fibrillation (AF). METHODS:The study involved reisolation of pulmonary veins (PV) with electrical reconnection and the creation of an anterior line (AL) in patients with anterior substrate or durable pulmonary vein isolation (PVI). RESULTS:In 24 patients (46% female, mean age 67 ± 10 years, 67% persistent AF), successful reisolation of 27/27 (100%) reconnected PVs was performed. In 19 patients AL ablation was performed, with bidirectional block in 16/19 (84%) patients, a median ablation time of 26 [21, 33] min, and first-pass bidirectional block in 13/19 (68%) patients. Acute AL reconduction occurred in 8/19 (42%) patients; among these 8 patients, a subsequent sustained block of the AL was achieved in 5/8 (63%) patients. Ultra-high-density electroanatomical mapping revealed homogenous, but relatively large low-voltage areas in the ablated regions. Median procedure, LA dwell, and fluoroscopy times were 100 [90, 109] min, 83 [75, 98] min, and 10 [8, 13] min, respectively. No major or minor complications occurred. CONCLUSION:This study demonstrated feasibility, acute efficacy, and safety of point-by-point PFA for repeat PVI and AL ablation. Further studies are warranted to assess the long-term durability and comparison with established ablation methods.