Anterior-Posterior Versus Anterior-Lateral Electrodes Position for Electrical Cardioversion of Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials

Background: The optimal electrodes position for elective direct current (DC) cardioversion of patients with atrial fibrillation (AF) remains uncertain. Methods: An electronic search of MEDLINE, EMBASE and COCHRANE databases was performed through March 2022 for randomized trials that examined the outcomes of anterior-posterior (AP) versus anterior-lateral (AL) electrodes position during cardioversion of (AF). The main outcome was the success rate of cardioversion. Data were pooled using random effects model. Results: The final analysis included 10 RCTs with a total of 1677 patients. There was no difference in the rate of successful cardioversion between the AP versus AL groups (86.6 vs 87.9 %; RR 1.00; 95 % Confidence Interval (CI) 0.95 to 1.06). Subgroup analysis by the shock waveform showed no significant interaction between monophasic and biphasic waveforms (P-intercation = 0.23). meta-regression analyses showed no effect modification of primary outcome according to body mass index (p = 0.15), left atrial diameter (p = 0.64), valvular heart disease (p = 0.34), lone AF (p = 0.58), or the duration of AF (p = 0.70). There was no significant difference between the AP and AL electrode position groups in successful cardioversion at low energy (RR 0.94; 95 % CI 0.74 to 1.19), the number of the delivered shocks (standardized mean difference [SMD]-0.03; 95 % CI-0.32 to 0.26) or the mean energy of the delivered shocks (SMD-0.11 and 95 % CI-0.30 to 0.07). There was lower transthoracic impedance with AP versus AL electrode position (SMD-0.28; 95 %CI-0.47 to-0.10). Conclusion: Meta-analysis of randomized data showed no difference between AP and AL electrode positions in the success rate of DC cardioversion of AF. Either AP or AL electrode positions should be acceptable approaches for elective DC cardioversion of patients with AF.