Reverse Prediction of Ion Channel Remodeling in Patients With Atrial Fibrillation Utilizing Monophasic Action Potential and Mathematical Modeling

After ordinary procedure for electrophysiologic study or catheter ablation, the investigators will replace conventional catheter to monophasic action potential (MAP) recording catheter through right femoral sheath. MAP recording catheter is introduced to endocardial surface of atrium, and we record atrial MAP at variable pacing cycle lengths: steady state cycle lengths of 600, 400, 300, 240, 220, 240, 260, 300, 400 and 600 ms. At each cycle length, pacing was applied for 20 sec. It takes less than 5 min to acquire MAP recordings.