Ablation and Left Atrium Reduction During Mitral Valve Surgery for Atrial Fibrillation

Inclusion Criteria: * Able to sign Informed Consent and Release of Medical Information forms * Age ≥ 18 years * Clinical indications for mitral valve surgery for organic mitral valve disease Note: May include need for surgical management of functional tricuspid regurgitation or patent foramen ovale. Surgical intervention may be performed via sternotomy or minimally invasive procedure. * a) Persistent atrial fibrillation (AF) within 6 months prior to randomization, defined as non self-terminating AF lasting greater than 7 days but no more than one year, or lasting less than 7 days but necessitating pharmacologic or electrical cardioversion. Duration of AF must be documented by medical history and Presence of AF must be documented by a direct electrocardiographic assessment within 6 months prior to randomization. b) Longstanding persistent AF is defined as continuous AF of greater than one year duration. Duration of AF must be documented by medical history and Presence of AF must be documented by a direct electrocardiographic assessment upon arrival in the OR. * left atrial diameter \> 65mm * Able to use heart rhythm monitor Exclusion Criteria: * AF is paroxysmal * AF without indication for mitral valve surgery * Concomitant coronary artery bypass grafting (CABG), aortic arch or aortic valve procedure * Previous catheter ablation for AF * Redo cardiac surgery * Left ventricle ejection fraction (LV EF) \< 35% * Life expectancy of less than one year * Mental impairment or other conditions that may not allow subject to understand the nature, significance, and scope of study