The purpose of this study is to compare the clinical outcomes depending on catheter ablation strategy for repeat ablation procedure among the patients with recurred atrial fibrillation after de novo catheter ablation. After randomization, the investigators will conduct circumferential pulmonary vein isolation alone in a group, and additional posterior box isolation and anterior linear ablation in the other group. Non-pulmonary vein foci ablation will be done in all patients. The investigators will compare clinical recurrence rate, complication rate, and procedure time, etc.