Catheter ablation for atrial fibrillation (AF) is an effective rhythm control method that shows superior rhythm outcome than antiarrhythmic drug (AAD) treatment in drug-resistant AF. However, AF catheter ablation still has a substantial recurrence rate.

The current AAD use guidelines for AF management focus on the safety of drug use. However, if the AAD efficacy evaluation system using computer modeling reflecting the individual anatomy, electrophysiology, and histological characteristics of patients is practical, it will help to select a more effective AAD type or dose.

The purpose of this study is to conduct a prospective randomized clinical study on the efficacy and safety of computer modeling for optimal AAD selection in patients with recurrent AF after catheter ablation. The investigator will evaluate the efficacy of AAD simulations by comparing virtual AAD effect guided therapy and empirical AAD use in patients with recurrent AF after AF catheterization.

The investigator will test the virtual AAD effects in the computer simulations integrated by cardiac images and 3D electrophysiological maps obtained during de novo AF ablation. The investigator will compare the effects of the most potent AAD selected by virtual AAD simulation with those of empirical AAD.

A. Study design

1. Prospective randomization (Virtual AAD TEST group vs. Empirical AAD group )
2. Target number of subjects: 300 (150 per group)
3. Rhythm FU : 2012 ACC/AHA/ESC guidelines (Holter monitoring at the baseline, 2 month, and thereafter every 6 months; ECG if the patient has any symptom)
4. Anticoagulant therapy followed by 2014 ACC/AHA/ESC guidelines
5. All complications in each group will be evaluated including the re-hospitalization rate, cardioversion frequency, major cardiovascular event, and mortality rate.

B. Progress and rhythm/ECG follow-up

1. To be performed in accordance with the 2012 ACC/AHA/HRS guidelines for AF management
2. Follow-up at 2 weeks, 2 months, and thereafter every 6-month after medication.
3. Rhythm control at 2 months, and thereafter every 6-month follow-up with Holter after medication
4. If the patient complains of symptoms, ECG will be performed at any time, and rhythm follow-up will be carried out with a Holter or event recorder.

C. Follow-up All the patients will be followed-up at 2 weeks, 2, 6 months, and thereafter every 6 months. If the patient shows any symptom within the clinical study period, patient will visit the outpatient clinic. ECG will be performed at every outpatient visits, and 24-hour Holter or event recording will be performed 2months and every 6 months for 2 years, and every year after 2 years (2012 Heart Rhythm Society/EHRA/European Cardiac Arrhythmia Society Expert Consensus Statement guidelines). If atrial fibrillation or atrial tachycardia lasting more than 30 seconds is observed in 12-lead ECG or Holter, it will be evaluated as recurrence. Recurrence within 3 months after the procedure will be classified as early recurrence, and that after 3 months will be classified as clinical recurrence.

Inclusion Criteria:

1. The patients with 20~80 years old those recurred AF after catheter ablation
2. Patients who are suitable for sinus rhythm conversion and maintenance using AAD medications
3. Patients who had no history of serious side effects due to AAD medications before the procedure

Exclusion Criteria:

1. Permanent AF Patients
2. AF associated with significant structural heart disease with severe anomaly or hemodynamic effects
3. Patients expected to have serious side effects when using AAD due to sinus node dysfunction
4. Severe liver or renal failure
5. Patients with past cardiac surgery history
6. Patients who are unable to oral medication or have electrolyte abnormalities
7. Patients with active internal bleeding
8. Contraindications for anticoagulant therapy (administered anticoagulant drugs to prevent cerebral infarction) or AAD
9. Valvular AF (mitral stenosis> grade 2, mechanical valve, mitral valve repair)
10. Severe concomitant illness
11. Patients expected to live for less than one year
12. Patients with drug or alcoholism
13. Those who cannot read the agreement (literacy, foreigners, etc.)
14. Patients judged to be inappropriate for participation in clinical trials by other researchers' judgment