Background and aim of the study: The study aim was to evaluate the efficacy and outcome of radiofrequency (RF) atrial fibrillation (AF) ablation in patients undergoing mitral valve (MV) surgery.
Methods: Between March 2002 and December 2004, 61 patients (mean age 65.4 ± 10 years) underwent isolated endo-left atrial AF ablation using a unipolar RF device (Cardioblate®; Medtronic, USA) in conjunction with 34 MV repairs and 27 MV replacements. AF was paroxysmal in 13 patients (21%), and permanent in 48 (79%), with a mean duration of 3.6 ± 3.5 years. The etiology was degenerative in 35 patients (57%), rheumatic in 17 (28%), and ischemic in nine (17%). All patients received amiodarone postoperatively.
Results: No patients died during the study, and there were no thromboembolic complications. All patients had intraoperative conversion. Forty-one patients (67%) presented with postoperative relapse; definitive

conversion was achieved in 34 (83%) cases within three months. The overall success rate was 75.4% at 14 ± 8.8 months; success was greater in the MV repair group (85%) than in the MV replacement group (66.7%), though not significantly so (p = 0.09). Factors associated with definitive conversion included smaller left atrial size (p= 0.007), decreased left ventricular end-diastolic diameter (p = 0.04), and NYHA class I (p = 0.05). Age, AF duration and etiology were not associated with conversion, but associated coronary artery bypass grafting showed a strong trend towards significance (p = 0.07). In these patients, AF duration did not predict conversion to sinus rhythm.
Conclusion: Combined AF ablation with MV surgery is safe and effective. Although AF ablation seems more beneficial with MV repair, the success rate may vary significantly according to patient characteristics.

The Journal of Heart Valve Disease 2006;15:515-520