Comparison of Circumferential Pulmonary Vein Isolation Alone Versus Linear Ablation in Addition to Circumferential Pulmonary Vein Isolation for Catheter Ablation in Persistent Atrial Fibrillation: Prospective Randomized Controlled Trial

Inclusion Criteria: * Patients with persistent Atrial fibrillation (20\~80 years) * LA diameter \<55mm * patients possible to anticoagulation and anti arrhythmic drug Exclusion Criteria: * Structural cardiac disease * Contraindication to brain perfusion CT * Catheter ablation history for AF, * Cardiac surgery for AF * active internal bleeding * Impossible to anticoagulation or antiarrhythmic drug * valvular AF (MA\> GII, Mechanical valve, Mitral valve replacement) * Patients with severe medical disease * Expected survival \< 1year * Severe alcoholics, drug addiction