Clinical application of low energy intracardiac cardioversion of atrial fibrillation / 介入放射学杂志

ABSTRACT

Objective To evaluate the efficacy and safety of low energy intracardiac cardioversion in persistent atrial fibrillation. Methods Low energy intracardiac cardioversion was performed by delivering R wave synchronized biphasic shocks in 7 patients(4 men, 3 women) with persistent atrial fibrillation. Prior to the procedure, all patients underwent transesophageal echocardiographic examinations to rule out the presence of intracardiac thrombus and received subcutaneous injection of low molecular weight heparin for 3 5 days. Two custom made 6 Fr catheters(Rhythm Technologies of Getz, USA) were used for de fibrillation shock delivery. One catheter was positioned in the lower right atrium so that the majority of the catheter electrodes had firm contact with the right atrial free wall. The second catheter was placed randomly either in coronary sinus through right internal jugular vein or in the left pulmonary artery through femoral vein. In addition, a standard diagnostic 6 F quadropolar catheter was placed at the right ventricular apex for ventricular synchronization and postshock ventricular pacing. Shocks were delivered by Implant Support Device(Model 4510, Teleceronics). After conversion, all patients were treated with intravenous amiodarone in the first 24 hours followed by oral administration. Results In all 7 patients cardioversion of atrial fibrillation to sinus rhythm was successfully obtained. A mean of 2?1 shocks per patient has been delivered with a total amount of 13 shocks. The average delivered energy was 7.8?2.2 Joules. No complication occurred. At a mean follow up of 18?9 months, 4 of the 7 patients treated successfully showed sinus rhythm there after. Atrial fibrillation recurred in 3 patients at the second, fifth day and eighth month after cardioversion. Conclusions Low energy intracardiac cardioversion is effective and safe, and can be easily performed in patients without geneal anesthesia. It offers a new option for restoring sinus rhythm in patients with persistent atrial fibrillation.