CACAF2 Study: Catheter Ablation for Cure of Atrial Fibrillation

Inclusion Criteria: * 18-70 years * Written informed consent * One documented relapse of atrial fibrillation (AF) during antiarrhythmic drug therapy after an electrical cardioversion Exclusion Criteria: * Permanent atrial fibrillation * Patients who had tried \>1 antiarrhythmic drug (Class I or Class III). * AF was the sole rhythm for \>6 months before the enrollment. * Previous ablation for AF. * AF is deemed secondary to a transient or correctable abnormality including electrolyte imbalance, trauma, recent surgery, infection, toxic ingestion, and endocrinopathy. * Patients who have fibrillation episodes triggered by another uniform arrhythmia (eg, atrial flutter or atrial tachycardia). * Patients with intra-atrial thrombus, tumor, or another abnormality that precludes catheter introduction. * Patients with Wolf-Parkinson-White syndrome. * Patients awaiting cardiac transplantation. * Congestive heart failure (CHF) New York Heart Association (NYHA) Class II-III-IV or ejection fraction (EF) \<40%. * Patients with unstable angina or acute myocardial infarction within 3 months. * Patients with cardiac revascularization or other cardiac surgery within 6 months. * Patients with heart disease in which corrective surgery is anticipated. * Patients in whom appropriate vascular access is precluded. * Pregnant women. * A separate requirement for antiarrhythmic drug treatment, which will require an antiarrhythmic drug not previously tried for AF suppression. * Prior atrial surgery. * Contraindication to treatment with warfarin or other bleeding diathesis. * Renal failure requiring dialysis. * Hepatic failure. * Participant in investigational clinical or device trial. * Unwilling or unable to give informed consent. * Inaccessible for follow-up. * Psychological problem that might limit compliance. * Active abuse of alcohol or other drugs which may be causative of AF. * An implanted device (pacemaker or cardioverter-defibrillator). * Left atrial diameter (anteroposterior) \>50 mm.