Monopolar and bipolar radiofrequency ablation surgery: 3-year experience in 90 patients with permanent atrial fibrillation.

Objective: In our population, permanent atrial fibrillation (pAF) is a serious concomitant problem in patients scheduled for open heart surgery. The high incidence necessitates reliable methods of treating pAF efficiently. We report our 3-year experience with a safe concept of using monopolar and bipolar radiofrequency (RF) ablation procedures.

Methods: Ninety patients (mitral, n = 56; aortic, n = 22; aortic and mitral, n = 1; coronary artery bypass grafting, n = 11) underwent either monopolar (n = 77) or, recently, bipolar (n = 13) RF ablation procedures that produced encircling isolation lesions around the left and the right pulmonary veins (PVs) and a connection line between the two. Amiodarone was given for 3 months after surgery.

Results: Hospital mortality was 2.2%. At follow-up, 75% of the patients were in stable sinus rhythm (SR). Preoperative pAF duration, etiology of heart disease, and type of RF energy application were not predictive of the risk of persisting pAF after surgery. Whereas patients (50 of 90) with small preoperative left atrial (LA) diameters (<56 mm) had SR in almost 90% of cases, large preoperative LA diameters (>or=56 mm; 40 of 90 patients) were associated with a significant risk of persisting pAF (P < .05).

Conclusion: Particularly in cases of small preoperative LA diameters, isolation of the PVs using either monopolar or bipolar RF ablation procedures in combination with amiodarone therapy represents a safe and efficient option for curing pAF in patients undergoing open heart surgery.