Electrical gaps in recurrence of atrial tachyarrhythmias after Maze surgery: regional patterns and clinical significance.

The Maze procedure is a well-established technique for treating atrial fibrillation; however, atrial tachyarrhythmias can recur postoperatively. This study analyzed the mechanisms of recurrence in patients who underwent electrophysiological studies and catheter ablation following the Maze procedure. Among 88 patients who underwent treatment with a modified Maze procedure, 42 developed recurrent atrial tachyarrhythmias. Among these, 18 underwent electrophysiological studies and simultaneous transcatheter radiofrequency ablation. The median period between the Maze procedure and catheter ablation was 29 months. Macro-reentrant circuits were identified in 12 patients (67%) with or without atrial fibrillation. Most patients (n = 15, 83%) had more than one conduction gap. The most frequently identified gap was around the left inferior pulmonary vein (n = 10, 56%), followed by the peri-coronary sinus area (n = 8, 44%), and the mitral isthmus area (n = 5, 28%). Catheter ablation targeting these gaps successfully eliminated tachyarrhythmias in 15 (83%) patients. At a follow-up examination 49 months after catheter ablation, 14 patients (78%) had no recurrence of tachyarrhythmia. An electrophysiological study revealed conduction gaps in patients with recurrent atrial tachyarrhythmia after the Maze procedure. Modifications to the Maze procedure should include meticulous ablation around the left inferior pulmonary vein orifice, mitral isthmus, and coronary sinus where conduction gaps frequently occur. In cases of recurrence, catheter ablation targeting the lesion effectively controlled the tachyarrhythmia.