A COMPARISON OF TRANSVENOUS ATRIAL DEFIBRILLATION OF ACUTE AND CHRONIC ATRIAL-FIBRILLATION AND THE EFFECT OF INTRAVENOUS SOTALOL ON HUMAN ATRIAL DEFIBRILLATION THRESHOLD

The comparative efficacy and safety of transvenous defibrillation for acute and chronic AF and the effect of antiarrhythmic agents on this t herapy have not been evaluated. Transvenous atrial defibrillation was performed in 25 patients with chronic AF and 13 patients with acute AF by delivering R wave synchronized, biphasic shocks between the right atrium and coronary sinus. The lowest energy and voltage resulting in successful defibrillation were considered to be atrial defibrillation threshold (ADFT). Intravenous sotalol (1.5 mg/kg) was then given over 15 minutes and ADFT was determined again. The mean ADFT was 1.5 J and 3.6 J for acute and chronic AF, respectively, and the threshold was hi ghly reproducible. Sotalol reduced ADFT in patients with acute AF whil e the reduction in chronic AF group was not significant. There was no significant increase in creatinine kinase nor reduction in blood press ure, but prolonged pause after successful defibrillation required vent ricular supporting pacing. We conclude that transvenous atrial defibri llation is a safe and effective means for defibrillating both acute an d chronic AF. ADFT was lower in acute AF than in chronic AF. ADFT was highly reproducible during repeated defibrillation. Sotalol reduced AD FT in acute AF and to a lesser extent in chronic AF, and increased the defibrillation success rate. Ventricular pacing will often be require d because of prolonged pause after successful defibrillation.