Intraoperative radiofrequency ablation for the treatment of atrial fibrillation during concomitant cardiac surgery

Background. Radiofrequency ablation has been recently introduced as an alternative to the surgical maze procedure to eliminate atrial fibrillation (AF). The purpose of this study was to examine the effectiveness of unipolar radiofrequency ablation in patients with AF undergoing open heart surgery. Methods. A retrospective review was performed on 54 patients undergoing radiofrequency ablation with concomitant cardiac operations from March 2002 through July 2003. Forty-two patients (77.8%) received left atrial ablation, and 12 (22.2%) received biatrial ablation. Results. Mean duration of preoperative AF was 46.3 +/- 44 months; 23 (42.6%) had AF 5 years or more, 32 (59.3%) had continuous AF, and 12 (22.6%) had a preoperative left atrial diameter of 6.0 cm or greater. At discharge, 33 patients (70.2%) were free from AF, 30 (62.5%) were in normal sinus rhythm, and 6 (12.7%) required a new pacemaker. Mid-term follow-up was available in 44 (93.6%) patients, with a median follow-up of 8.7 months (range, 3 to 22 months). At follow-up, 34 (77.3%) patients were free from AF. There were no significant differences in freedom from AF in patients with continuous versus intermittent AF or duration of 5 or greater years versus less than 5 years. In patients with isolated mitral valve surgery and radiofrequency ablation, 22 (88.0%) were free from AF compared with 12 (63.2%) with other operations (p = 0.074). In patients with left atrial diameter less than 6.0 cm, 30 (88.2%) were free from AF compared with 4 (40%) with left atrial diameter of 6.0 cm or greater (p = 0.006). Conclusions. Radiofrequency ablation is an effective surgical option for the treatment of continuous or intermittent AF. The elimination of AF using radiofrequency ablation is most successful in patients undergoing isolated mitral valve surgery with preoperative left atrial diameter less than 6.0 cm. (c) 2005 by The Society of Thoracic Surgeons.