 Specific Aims: The primary objective of this registry is to determine the percentage of patients who are free from atrial fibrillation AF at 6 and 12 months following a surgical ablation procedure when the patient has a history of failing one or more previous catheter based ablations for AF. The first 3 months following surgical ablation will be a blanking period; any arrhythmia occurring during this time will not be used to determine success. 