Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation

Background In biphasic external cardioversion (CV) of atrial fibrillation (AF), the influence of different electrode positions on efficacy and incidence of early recurrent atrial fibrillation is not known. This study compared anteroposterior (AP) vs anterolateral (AL) electrode positioning. Methods Consecutive patients referred for CV of persistent AF were randomized either to an AP or an AL electrode position. Biphasic external CV was performed with standardized electrode positions and rising energy delivery. Results Both groups (N = 123, mean age 66 years, 71% male, 83% with structural cardiovascular disease or hypertension) did not differ concerning age, sex, body mass index, chronic antiarrhythmic therapy, duration of AF, left ventricular ejection fraction, and left atrial diameter. Cumulative success rates were comparable (AP 94.9% vs AL 95.2%, P = ns). First-shock efficacy did not differ (AP 78.3% vs AL 74.6%, P = ns). Early recurrent atrial fibrillation (AF relapse <1 minute after successful CV) occurred in 8.1% (AP 11.6% vs AL 4.8%, P = ns). Mean number of shocks was 1.3 per patient with the AP configuration and 1.4 per patient with the AL configuration (P = ns). Mean cumulative energy delivery was also comparable (AP 171 WS vs AL 198 WS, P = ns). Conclusions Both electrode positions are similar in biphasic external CV of AF with regard to acute success and early recurrent atrial fibrillation. Also, the number of shocks needed and energy delivery are comparable with both electrode configurations.