• Subject must be between 18 and 85 years of age

• Subject is willing and capable of providing Informed Consent to undergo study procedures which include the potential for surgical AF ablation, and completion of follow-up visits as specified in the clinical study protocol

• Subject has history of documented paroxysmal atrial fibrillation (AF that is intermittent and terminates within ≤ 7 days of onset) or persistent/longstanding persistent atrial fibrillation (AF that is continuous and sustains for \> 7 days and requires intervention) within one year prior to enrollment. Documentation may include ECG, transtelephonic monitor (TTM), Holter monitor or telemetry strip from the study hospital or an outside physician

• Subject is scheduled to undergo non-emergent cardiac surgical procedure(s) to be performed on cardiopulmonary bypass including open-heart surgery via sternotomy for one or more of the following: Mitral valve repair or replacement, Aortic valve repair or replacement, Ascending aortic aneurysms, Atrial Septal Defect (ASD)/Patent Foramen Ovale (PFO) or Coronary artery bypass procedures

• Left ventricular ejection fraction ≥ 30% (determined by echocardiography or cardiac catheterization performed within 60 days of enrollment as documented in patient medical history)

• Subject has a life expectancy of at least 5 years

• Subject currently lives within a reasonable commuting distance of the investigational site and plans to remain geographically stable through 12 month follow up