DAPPAR AF Dabigatran for Peri Procedural Anticoagulation During Radiofrequency Ablation of Atrial Fibrillation

Inclusion Criteria: * Patients age 18 or greater. * Patients undergoing first-time catheter ablation for AF. * Patients with paroxysmal or persistent AF. Paroxysmal AF will be defined as self-terminating episodes less than 7 days duration. Persistent AF will be defined as episodes that last longer than 7 days duration or episodes requiring termination by electrical or chemical cardioversion. * Patients with symptomatic AF that is refractory to at least one antiarrhythmic medication. "Symptomatic" patients are those who have been aware of their AF anytime within the last 5 years prior to enrollment. Symptoms may include, but are not restricted to, palpitations, shortness of breath, chest pain, fatigue, left ventricular dysfunction, or other symptoms, or any combination of the above. * At least one episode of AF must have been documented by ECG, Holter, loop recorder, telemetry, or transtelephonic monitoring within 24 months of entry in the trial. * Patients must be able and willing to provide written informed consent to participate in the clinical trial. Exclusion Criteria: * Patients with AF felt to be secondary to an obvious reversible cause (e.g. thyroid disease, post-surgical). * Patients with contraindications to systemic anticoagulation with heparin or a direct thrombin inhibitor. * Patients with severe renal impairment (creatinine clearance of \<30 ml/min) * Patients with left atrial size \>/= 60 mm (2D echocardiography, parasternal long axis view). * Patients who ar…