WATCHMAN Implantation During Hybrid Ablation

Inclusion Criteria: * Documented paroxysmal or (long-standing) persistent non-valvular atrial fibrillation, * Eligible at least for short-term OAC therapy, * No other conditions that would require long-term OAC therapy, suggested by current standard medical practice, and thus is eligible to stop OAC if the LAA is sealed, * Calculated CHA2DS2-VASc score of 1 or more, * 18 years of age or older, able and willing to provide written informed consent. Exclusion Criteria: * Current New York Heart Association Class IV Congestive Heart Failure, * Current thrombocytopenia (\< 100x10E9/L) or anemia (hemoglobin \<6.2 mmol/L), * Active infection or sepsis, * Resting heart rate \> 110 beats per minute, * Cerebrovascular accident (CVA) or transient ischemic attack (TIA) within the last 30 days, * Recent myocardial infarction (within 3 months), * Transient case of AF (i.e., secondary to recent cardiac surgery (within 3 months)), * Planned cardioversion 30 days post implant of the WATCHMAN Device, * Implanted mechanical valve prosthesis, * History of obliterated LAA, * History of heart transplantation, * Symptomatic carotid disease (i.e., carotid stenosis \>50% associated with ipsilateral transient or visual ischemic attack evidenced by amaurosis fugax, ipsilateral hemispheric TIAs or ipsilateral stroke within 6 months), * Necessity to use long-term OAC, * Contraindication for use of OAC or dual anti-platelet therapy, * Contraindication for use of aspirin, * Pregnancy or planned pregnancy during the course of the investigation, * Life expectancy less than 2 years, * Participation in any other clinical study involving an investigational drug or device. Echocardiographic Exclusion Criteria (as assessed via transthoracic echocardiography (TTE) or TEE) for this study are: * Left ventricular ejection fraction (LVEF) \< 30%, * Intracardiac thrombus as visualized by TEE within 2 days prior to implant, * High risk patent foramen ovale, * Current atrial septal defect and/or previous atrial septal repair or closure device, * Significant mitral valve stenosis (i.e., MV 4. 5 cm2), * Existing pericardial effusion of \>3 mm, * Complex atheroma with mobile plaque of the descending aorta and/or aortic arch, * Cardiac tumor.