Impact of the Pulmonary Vein Isolation on Exercise Capacity in Patients With Chronic Atrial Fibrillation

III. Goals of the Project The purpose of this study is to determine whether pulmonary vein isolation with radiofrequency ablation will improve exercise capacity and endothelial function in patients with chronic atrial fibrillation. We hypothesize that exercise capacity and endothelial function will improve in patients with chronic atrial fibrillation following pulmonary vein isolation.

IV. Background and Significance:

Easy fatigability is a frequent complaint in patients with atrial fibrillation (AF). Prior studies have demonstrated that exercise capacity in patients with "lone atrial fibrillation" is less than that in healthy matched controls. Other investigators have also shown the adverse effect of AF by comparing peak oxygen uptake VO2 prior to and after cardioversion. At present, the majority of studies have focused on patients in whom with AF with either mild cardiovascular disease or congestive failure. No study to date has assessed if pulmonary vein isolation (PVI) via intracardiac ablation is able to improve exercise capacity in patients with chronic LSP-AF.

This prospective registry will assess exercise capacity in patients with chronic AF (CAF) over a minimum period of 3 months; prior to and after PVI. Chronic AF is defined as those patients who have an unsuccessful cardioversion and/or an ongoing AF episode (e.g. a year or more). The observed results will be used to establish a better understanding of overall quality of life and exercise tolerance prior to and after ablation. This registry may be further expanded in the future and in a second study to assess exercise tolerance in patients with CAF who have been treated with alternative treatment strategies. The findings from this study may begin to pave the way for future clinical practice changes to best manage patients with CAF.

Description of the procedures: Patients will be required to fast and refrain from smoking at least 4 hours prior to each testing session.