Inclusion Criteria:  Subjects planned for an AF catheter ablation procedure, with a documented history of AF. Diagnosis must be confirmed within 12 months before enrollment. Subjects between 18 and 75 years of age, inclusive  Exclusion Criteria:  Patients who have contraindications to open heart surgery Patients from an Intensive Care Unit Patients with active systemic infection (sepsis) Patients requiring concomitant right atrial ablation (as determined before the procedure) Patients who have had previous ablation in the left atrium Patients who are post-heart transplant or who are awaiting cardiac transplantation or other cardiac surgery Patients with cardiac implants that may interfere with device delivery or positioning (e.g. atrial septal defect closure device, left atrial appendage occluder) Patients with mitral valve prolapse or other heart valve abnormalities excepting mild to moderate mitral regurgitation Patients with New York Heart Association Class III or IV heart failure History of a documented thromboembolic event, including stroke or transient ischemic attack (TIA) Bleeding disorder history Patients with a known sensitivity to anesthesia or neuromuscular block agent Currently undergoing long-term treatment with steroids, not including intermittent use of inhaled steroids for respiratory disease Myocardial infarction within the last three months Atrioventricular (AV) block II° or III° Atrial flutter Left ventricular ejection fraction (LVEF) of less than 35% Unstable angina