Discerning Symptomatic and Asymptomatic Episodes Pre and Post Radiofrequency Ablation of Atrial Fibrillation

Inclusion Criteria: * Age \> 18 years old. * First-time ablation procedure for AF. * Symptomatic AF which has been refractory to at least one antiarrhythmic medication. "Symptomatic" patients should be patients who feel that they are aware of when they are in or out of AF. Symptoms may include palpitations, shortness of breath, chest pain, fatigue, or other symptoms, or any combination of the symptoms listed above. * Patients must have paroxysmal or persistent AF. Paroxysmal patients should have had at least 4 episodes of AF in the 6 months prior to assessment/ablation. Paroxysmal AF is defined as AF which spontaneously terminates within 7 days. Persistent AF is defined as AF which sustains for longer than 7 days, or AF lasting less than 7 days which requires either pharmacologic or electrical cardioversion. * At least one episode of AF must have been documented by ECG or Holter within 12 months of inclusion in the study. * No contraindication to systemic anticoagulation with heparin or coumadin. * Patients must be able and willing to provide written informed consent to participate in the study. Exclusion Criteria: * Patients with permanent atrial fibrillation. Permanent AF is defined as chronic, persisting AF (typically more than 1 year) for which cardioversion (pharmacologic or electrical) has failed or will never be attempted. * Patients with AF felt to be secondary to an obvious reversible cause. * Patients with contraindications to systemic anticoagulation with hepari…