Electrophysiological Effects Of Ibutilide And Its Efficacy For Termination Of Atrial Fibrillation/Flutter

10 patients who had underwent catheter radiofrequency ablation due to left ventricular free wall accessory pathway, were administered intravenously with Ibutilide. The electrophysiological datas were recorded before and at 0min, 15min and 30min after injection of ibutelite. The results confirmed that AERP, VERP, RR, QTc and QT interval evoked by ventricular pacing were prolonged simultaneously after ibutilide injection, whereas PA, AH, HV interval and AVN-ERP were intact, which illustrated that ibutilide has minimal effect on the normal cardiac conduction system.Twenty-five consecutive patients of AF/AFL were recruited, All the patients were randomly assigned to ibutilide group or propafenone group. The conversion rate of arrhythmics, the extent of decreasing ventricular rate and the side effect were detailed after administer of both drugs respectively. This study establishes the superior efficacy and fast converting time of ibutilide over propafenone when administered to convert AF/AFL to sinus rhythm. The converted cases in ibutilide group had shorter AF duration and smaller left atrial diameter in compared with unconverted patients in the same group. QTc interval prolonged significantly at 0min and 10min after injection of ibutilide and came to the normal until 4h later. One patient presented torsade de pointes after injection of ibutilide. It was suggested that electrocardio-monitoring should be no less than 6h after ibutilide injection.