Methods We retrospectively studied a total of 81 patients with chronic atrial fibrillation who underwent open cardiac surgery with concomitant RF ablation between January 2007 and March 2011. Fifty-eight patients received bipolar RF ablation and 23 received monopolar RF ablation, respectively. The sinus rhythm restoration rate, the procedural duration, the frequency of severe perioperative complications, and mortality were compared between the two groups.Results The sinus rhythm restoration rate did not differ significantly between the two groups after follow-up of 15.1 ± 12.6 months (P=0.199). The frequencies of severe perioperative complications and mortality were also similar in the two groups. The total procedural time using bipolar RF ablation was significantly shorter than that using monopolar ablation (19.7±4.6 minutes vs. 28.1±8.5 minutes, P< 0.001).Conclusions Both monopolar and bipolar RF ablation are safe and effective in treating chronic atrial fibrillation patients during open cardiac surgery, but bipolar RF ablation is more convenient in practice.

Key words: atrial fibrillation, radiofrequency ablation, cardiac surgery, Maze procedure