[Totally endocardial surgical ablation of atrial fibrillation combined with mitral valve surgery. Our experience with the Cardioablate pen].

Abstract

Background: Atrial fibrillation (AF) is the most common arrhythmia found in mitral valve (MV) disease, occurring in 30 to 85% of patients. Since 1999, AF has been ablated using monopolar epicardial-endocardial radiofrequency. In this study, we describe our own endocardial experience of using the Cardioablate monopolar radiofrequency irrigated pen for the ablation of AF in patients undergoing MV surgery and an analysis of the short and mid-term results.

Methods: From August 2002 to February 2004, a monopolar radiofrequency pen was used to ablate AF in 29 patients undergoing MV replacement or repair (24 females, 82.7%). Preoperative AF was paroxysmal in 27.6% of the patients, persistent in 13.8%, and permanent in 58.6%. The mean left atrial diameter was 65.8 +/- 11.4 mm (range 40-92 mm). In all the patients the ablation lines were created under conditions of extracorporeal circulation and aortic cross-clamping and carried out according to the Alfieri's set. The left atrial appendage was resected or excluded. Endocardial ablation increased the duration of the operation by a mean time of 14.8 +/- 2.7 min with an average time of 7.3 +/- 1.4 min for radiofrequency application.

Results: All patients left the operating room with ginus rhythm (SR) or with atrioventricular pacing. Perioperative AF was common, affecting 51.7% of patients. Six patients required electrical cardioversion. Both early postoperative death (2 patients, 6.8%) and complications were not procedure-related. At discharge, all patients were in SR. The mean follow-up was 14.8 +/- 5.2 months (range 7-25 months). Only 3 patients (11.1%) lost SR within the first 6 months of follow-up but it was recovered in all cases through the use of electrical cardioversion (2 patients) or antiarrhythmic drugs.

Conclusions: The totally endocardial monopolar radiofrequency pen facilitates a quick and safe AF ablation in patients with MV disease. Its only theoric limitation concerns the transmurality of the lesions. Perioperative AF is common and should be treated aggressively. By 6 months postoperatively, 100% of patients are free of AF or atrial flutter with recovery of normal atrial contraction. More patients and longer follow-up are necessary to document the long-term results of this simple procedure.