AV node ablation and pacemaker implantation after withdrawal of effective rate-control medications for chronic atrial fibrillation: effect on quality of life and exercise performance.

We assess whether AV node ablation and pacemaker implantation after discontinuation of effective rate-control medical therapy for chronic atrial fibrillation had a positive impact on quality of life and exercise performance. To assess the possibility of a placebo effect following pacemaker implantation, the study included three groups of patients. Group 1 underwent an echocardiogram, treadmill exercise, and quality of life measurement 1 month prior to and 6 months following AV node ablation and pacemaker implantation associated with discontinuation of rate-control medications. Group 2 underwent AV node ablation and pacemaker implantation without discontinuation of antiarrhythmic rate-control drugs. Group 3 underwent pacemaker implantation without performing AV node ablation and continuing rate-control medical therapy. At the 1- and 6-month evaluation, the patients in group 1 showed a significant improvement of left ventricular ejection fraction, quality of life, and activity scores. The exercise duration and the maximal VO2 consumption, however, did not change significantly. A slight improvement of the quality of life and physical activity scores was observed in the group undergoing AV node ablation without withdrawal of medications. However, no significant changes were observed in the group receiving only the pacemaker without modification of medical therapy and with intact AV node conduction. In conclusion, in patients with chronic atrial fibrillation, discontinuation of effective rate-control medical therapy followed by AV node ablation and permanent pacing appeared to improve quality of life and activity scores despite no change in exercise duration. The improvement observed does not seem to reflect a placebo effect.