Abstract 2478: Time Course, Mechanisms and Management of Recurrent Atrial Arrhythmias Following the “Mini-Maze” Procedure
Introduction Minimally invasive thoracoscopic (“mini-Maze”) procedures have evolved for surgical treatment of atrial fibrillation (AF). We describe the spectrum of recurrent atrial tachyarrhythmias (AT) following the mini-Maze.
Hypothesis Fifty patients underwent bipolar radiofrequency (RF) ablation of the pulmonary vein antrum (PVI), parasympathetic ganglionated plexi, and ligament of Marshall. Eighteen patients (36%) had symptomatic ATs and 11 underwent electrophysiology study 100 to 948 days post-operatively (mean 354). We hypothesized that post-operative ATs could be successfully identified and ablated.
Results Twelve symptomatic arrhythmias were identified in 11 patients 95 to 424 days (mean 209.3) after mini-Maze (Table⇓). All 6 patients with recurrent AF had either 2 or 3 veins with electrical reconnection and 5 of 6 had reconnection in the left superior pulmonary vein. Pulmonary vein reconnection was seen in 53% of left PVs and 47% of right PVs. On average, 26.6% of each pulmonary vein reconnected and most showed conduction delay. Post-operative atrial flutters were due to a macroreentrant circuit, primarily in the right atrium. All patients underwent mapping and ablation as shown with no complications. Following catheter ablation, 2 patients had symptomatic recurrence of AT.
Conclusions In conclusion, symptomatic AT occurs in about one third of patients after minimally invasive thoracoscopic PVI. Pulmonary vein reconnection accounts for most recurrences followed by atrial macroreentry. Post-operative AT appears amenable to catheter ablation, with good long term success.