Efficacy of High Density Voltage and Fractionation Map Guided Ablation in Patients With Atrial Fibrillation

Inclusion Criteria: * 1\. Age over 20 years old and under 80 years old 2. Patients with non-valvular atrial fibrillation 3. Patients having AF even after receiving continued treatment with at least 1 antiarrhythmic drug for more than 6 weeks 4. Patients who can understand the information sheet and consent form on the need and procedure of catheter ablation and submitted them 5. Patients who are available of follow-up at least for more than three months after catheter ablation Exclusion Criteria: 1. Patients unsuitable for catheter ablation because the size of left atrium is over 6.0 cm 2. Patients unsuitable for catheter ablation due to previous history of pulmonary surgery or structural heat disease. 3. Patients who cannot receive standard treatments such as anticoagulation therapy which need to be continuously performed prior to radiofrequency catheter ablation 4. Patients in the subject group vulnerable to clinical study 5. Patients who had undergone a prior catheter ablation for atrial fibrillation