Abstract 12976: The Mechanism and Long-term Efficacy of Catheter Ablation in Patients With Atrial Tachycardia Following Full-Maze Surgery
Background: Although full-maze surgery for atrial fibrillation (AF) is highly effective in restoring sinus rhythm, atrial tachycardia (AT) may develop postoperatively. Catheter ablation is effective in eliminating such post-operative AT. However, long-term prognosis after successful ablation is unclear.
Method and Results: Between 1999 and 2012, catheter ablation was performed in 25 patients with AT that emerged late after full-maze surgery for AF. Two patients underwent full-maze procedure for lone AF with no other surgical indication. The remaining 23 patients underwent other surgical procedure concomitantly: valve surgery in 20 patients, ASD closure in 2 patients, and left atrial thrombectomy in 1 patient.
A total of 49 AT were mapped. The mechanism was macroreentrant AT utilizing residual conduction across the surgical lesion in 29, focal AT in 15, and scar related AT in 5. Acute success was achieved in 22 patients (88%). In 6 patients, repeated procedure was performed for recurrence, and a total of 13 recurred AT was mapped. Macroreentry utilizing insufficient surgical lesion was only 4, and the major mechanism was focal AT in 5 and scar-related AT in 4, that was not related surgical insufficiency. After the final procedure (1.3 ± 0.8 procedure), sinus rhythm was maintained in 18 of 25 patients (72%) during follow-up period of 3.3±2.9 years. AF developed in 5 patients (20%) 3.2 ± 2.6 years after the final procedure, and AT recurred in 2 patients (8%). AT/AF-free survival rate at 1, 4, and 8 years was 92%, 78%, and 48%, respectively.
Conclusion: Most frequent mechanism of the AT at the first session was macroreentry utilizing a gap at a surgical lesion, and the acute success rate of catheter ablation is high. However, AT that is not related to surgical lesion such as focal AT and sca-related AT and AF may occur after the first session, and long-term efficacy is limited. Limited long-term efficacy may be due to progression of atrial substrate.
- © 2013 by American Heart Association, Inc.