Catheter ablation of atrial fibrillation (AF) has been ,increased dramatically recently. However, it is an unpleasant procedure with intolerable pain without sedation. Propofol and fentanyl/midazolam have been widely used in painful clinical examination and cardiovascular procedures with established safety and efficacy. Propofol, alfentanyl and midazolam were administrated for catheter ablation in some electrophysiological labs for a less painful procedure. However, there is few published work on the sedation regimen for catheter ablation of AF.