Insight from Redo Ablation in Patients with Atrial Fibrillation

Background: This study sought to determine the electroanatomical characteristics of recurrent atrial fibrillation (AF) identified during redo Catheter ablation (CA) of AF. Methods: Of 1374 patients with CA of AF, 173 consecutive patients (12.6%) underwent redo CA were studied. One hundred forty seven (85.0%) patients underwent a 2nd repeat procedure, and 3rd and 4th and 5th repeat procedure was performed in 20 (11.6%), 5 (2.9%), and 1 (0.5%), respectively. Results: In 173 patients (54 ±11 years), 90 paroxysmal AF and 83 non paroxysmal AF were identified. The LA volume measured by 3-dimensional CT (106.3 ± 34.7ml) became significantly smaller than that at first CA (130.6 ± 50.3ml, P=0.02). In 2nd redo procedure, all PV reconnection was observed in 55 patients (38.2%). PV reconnection as etiology of recurred AF was not common, but its incidence was higher in patients who underwent redo <2 years (29.9% vs. 8.0%, P=0.06). PV stenosis was present in 23 of 173 patients (13.3%), which commonly developed at a single PV (65.2%), and mostly asymptomatic and often occurred in patients with carina ablation. Conclusions: The LA volume was significantly decreased at redo procedure. PV reconnection was not major etiology of recurrent AF, but commonly found in patients underwent redo <2 years. Asymptomatic PV stenosis was not uncommon. The result from redo ablation could guide more effective and safer ablation strategy.