1. Purpose of the study

1) To explore clinical recurrence associated clinical factors including age, sex, clinical, electrophysiological, anatomical, imaging, and serologic characteristics.

2) To develop simulation model to predict clinical recurrence and the efficacy of catheter ablation 2. Scientific evidence of the study

1. In atrial fibrillation patients, the maintenance of normal sinus rhythm showed significant reduction of mortality.
2. drug therapy with anti-arrhythmic drug showed many complications and side effect, thus non-drug therapy such as catheter ablation is developed.
3. catheter ablation has been performed for 10years world-wide, and showed superior treatment outcome compared with drug therapy.
4. clinical outcome after catheter ablation is affected not only by age, sex and underlying disease, but also by electrophysiologic, imaging, serologic and electroanatomical remodeling of the heart. However, there are few studies concerning these multifactorial variables.

3. Study population

Inclusion Criteria:

• patients who undergoing catheter ablation of atrial fibrillation due to symptomatic, drug refractory atrial fibrillation

Exclusion Criteria:

• patients who do not agree with study inclusion
• permanent AF refractory to electrical cardioversion
• AF with valvular disease ≥ grade 2
• patients with left atrial diameter greater than 60mm
• patients with age less than 19

Consecutive patients with atrial fibrillation who undergoing catheter ablation in Yonsei Cardiovascular hospital, Yonsei university health system, Seoul, Korea.