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

We assess whether AV node ablation and pacemaker implantation after discont inuation of effective rate-control medical therapy for chronic atrial fibri llation had a positive impact on quality of life and exercise performance. To assess the possibility of a placebo effect following pacemaker implantat ion, the study included three groups of patients. Group I underwent an echo cardiogram, treadmill exercise, and quality of life measurement 1 month pri or to and 6 months following AV node ablation and pacemaker implantation as sociated with discontinuation of rate-control medications. Group 2 underwen t AV node ablation and pacemaker implantation without discontinuation of an tiarrhythmic rate-control drugs. Group 3 underwent pacemaker implantation w ithout performing AV node ablation and continuing rate-control medical ther apy. At the 1- and g-month evaluation, the patients in group 2 showed a sig nificant improvement of left ventricular ejection fraction, quality of life , and activity scores. The exercise duration and the maximal VO2 consumptio n, however, did not change significantly. A slight improvement of the quali fy of life and physical activity scores was observed in the group undergoin g AV node ablation without withdrawal of medications. However, no significa nt changes were observed in the group receiving only the pacemaker without modification of medical therapy and with intact AV node conduction. In conc lusion, in patients with chronic atrial fibrillation, discontinuation of ef fective rate-control medical therapy followed by AV node ablation and perma nent 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.