Compare the efficacy of the left atrial Cox-Maze IV lesion set versus the Tampa 2 lesion set versus the EnCompass ablation alone, in the surgical treatment of atrial fibrillation at one year post-operatively.

This is a single center prospective, randomized trial to compare the outcomes, specifically the freedom from atrial fibrillation at one year, and possibly up to five years, of three different approaches to the cardiac surgical management of atrial fibrillation.

Several strategies to accomplish surgical ablation are acceptable and have been shown retrospectively to be successful. The Cox-Maze bi-atrial, left and right atrial lesions, ablation (whether III or IV) remains the gold standard by which all surgical ablations are compared. Further refinement in ablation technology and research has further suggested there is no difference between a left atrial ablation alone or bi-atrial ablation lesion set. For left atrial ablation alone, existent therapeutic options, which all meet equivalent standard of care, include a left atrial Cox-Maze IV , a Tampa 2 lesion set or utilizing a "box lesion" alone. Currently, there are no randomized, clinical trials demonstrating better efficacy (freedom from atrial fibrillation post-operatively) of one ablation strategy over another in patients undergoing cardiac surgery.

The rationale for the study is to demonstrate whether one ablation technique is more efficacious in the surgical treatment of AF. Should one technique prove superior it may clarify the question of which ablation strategy to utilize and encourage surgeons to implement a consistent approach to surgical ablation.

To our knowledge this study would be the first prospective, randomized trial in the United States comparing surgical lesion sets in the concomitant management of atrial fibrillation.

Inclusion Criteria:

• Adult patients with a history of preoperative atrial fibrillation, either paroxysmal or persistent, requiring concomitant surgical ablation who are scheduled to undergo cardiac surgical procedure(s) to be performed on cardiopulmonary bypass
• Utilizing sternotomy approach requiring cardiopulmonary bypass
• Male or Female subjects between age 18 to 85 years of age

Exclusion Criteria:

• LVEF < 25%
• LAVI > 59ml/m②
• Presence of Pacemaker/AICD
• History of VT/VF, WPW
• Re-operative cardiac surgery