This study is to evaluate acute and long-term safety and effectiveness of Left atrial appendage occlusion (LAA)with the AtriCure LAA Occlusion System. This device will be applied in patients with atrial fibrillation (AF), paroxysmal, persistent and permanent, undergoing cardiac surgery with a concomitant Maze/Ablation procedure.

Inclusion Criteria:

1. Documented history (paroxysmal, persistent or permanent) of AF [one episode within the last 12 months of enrollment]
2. Elective Maze procedure
3. Suitable anatomy
4. Able and willing to sign informed consent
5. Age over 18 years

Exclusion Criteria:

1. Patient from Intensive Care Unit with either:

   1. intra-venous catecholamines
   2. ventilator
   3. cardiac index <1.8 l/min.

2. Reoperative Cardiac Surgery

3. Systemic or Inflammatory disease

4. Dialysis

5. Recent myocardial infarction (< 21 days)

6. History of pericarditis

7. Patient taking part in any other device or drug study

8. Patient with known sensitivity or allergy to any of the device components

9. Pregnancy