Efficacy and Safety of Single Lead Internal Cardioversion Technique in Patients with Atrial Fibrillation Resistance to External Cardioversion

Internal cardioversion (ICV) has been suggested as an effective method to restore sinus rhythm in patients with atrial fibrillation (AF). Recently, a new single-lead system with a balloon-tipped cardioversion catheter was introduced. The aim of this study was to assess the feasibility and efficacy of the balloon-tipped single-lead ICV technique in patients with permanent AF. Eighteen patients (11 were female, mean age 59±14 years) with permanent AF were submitted to single-lead ICV after an unsuccessful external cardioversion attempt. A new balloon-tipped single-lead catheter (ALERT, EP MedSystems, Inc.) with distal and proximal shock electrodes and biphasic shocks ? 15 J was used for ICV. The distal shock array was placed in the left pulmonary artery and the proximal one placed into the right atrial tissue under fluoroscopy guidance. All patients were mildly sedated using midazolam. Internal shocks were R-wave synchronized to the single right ventricular (RV) electrode and delivered between distal and proximal array using a new external defibrillation system after the defibrillation impedance was tested.
RESULTS
In 14 of 18 pts (%77) sinus rhythm was restored with a mean energy of 9.3±5.4 J and mean of 4.2±2.3 shocks delivered. The mean fluoroscopy time was 4.6±2.2 min and mean shock impedance was 61±13 W. No complications occurred during the procedure.
CONCLUSION
Internal cardioversion using single-lead balloon-tipped catheter is a feasible and effective technique for permanent AF. This technique might increase and expand the clinical use of ICV in patients with permanent AF.