Patient population: Patients with persistent AF (defined as atrial fibrillation which is sustained beyond 7 days but no more than one year, or lasting less than 7 days but necessitating pharmacologic or electrical cardioversion, but lasting longer than 48 hours) should be documented either on 12-lead ECG, transtelephonic monitoring (TTM), ambulatory holter monitoring (HM) or telemetry strip and a physician's note showing continuous AF. Furthermore patients who have failed at least one Anti Arrhythmic Drug (AAD) (Class I or III) as evidenced by recurrent symptomatic AF or intolerable side effects of the AAD. Eligible patients who sign the study informed consent form will be randomized based on a 2:1 ratio into one of two study arms: