Catheter ablation of atrial fibrillation(AF)has beenincreased dramatically recently.However,it is anunpleasant procedure with intolerable pain withoutsedation.Propofol and fentanyl/midazolam have beenwidely used in painful clinical examination andcardiovascular procedures with established safety andefficacy.Propofol,alfentanyl and midazolam wereadministrated for catheter ablation in someelectrophysiological labs for a less painful procedure.However,there is few published work on the sedationregimen for catheter ablation of AF.Catheter ablation of AF guided by 3D electroanatomicalnonfluoroscopic mapping systems(CARTO,BiosenseWebster,USA)has been widely used.If the referencepatch on the back of the patient is moved,the left atrialgeometry of the 3D mapping system will lose theprecision in guiding the catheter.We carried out aprospective,randomized study to test the hypothesis thatconscious sedation with fentanyl/midazolam for catheterablation of AF had advantages over unconscioussedation/analgesia with propofol according to adverseinfluence on the ablative procedure.