An anterior-lateral defibrillation pad position is more effective for biphasic cardioversion of atrial fibrillation, according to a recent study published in the Circulation.
Smaller randomized studies have reported conflicting results regarding the optimal electrode position for cardioverting atrial fibrillation. However, anterior-posterior electrode position is widely used as a standard and believed to be superior to anterior-lateral electrode position. Therefore, a group of researchers aimed to compare anterior-lateral and anterior-posterior electrode position for cardioverting atrial fibrillation in a multicenter randomized trial.
In this multicenter, investigator-initiated, open-label trial, we randomly assigned patients with atrial fibrillation scheduled for elective cardioversion to anterior-lateral or anterior-posterior electrode position. The primary outcome was the proportion of patients in sinus rhythm after the first shock. The secondary outcome was the proportion of patients in sinus rhythm after up to four shocks escalating to maximum energy. Safety outcomes were any cases of arrhythmia during or after cardioversion, skin redness, and patient-reported peri-procedural pain.
The Results of the study are as follows:
The researchers randomized 468 patients. The primary outcome occurred in 126 patients (54%) assigned to anterior-lateral electrode position and in 77 patients (33%) assigned to anterior-posterior electrode position, a risk difference of 22 percentage-points, 95%-confidence interval: 13-30, P<0.001. The number of patients in sinus rhythm after the final cardioversion shock was 216 patients (93%) assigned to anterior−lateral electrode position and 200 patients (85%) assigned to anterior-posterior electrode position, a risk difference of 7 percentage−points, 95%−confidence interval: 2−12. There were no significant differences between groups in any safety outcomes.
Thus, the researchers concluded that anterior-lateral electrode position was more effective than anterior-posterior electrode position for biphasic cardioversion of atrial fibrillation. There were no significant differences in any safety outcome.
Reference:
Anterior-Lateral Versus Anterior-Posterior Electrode Position for Cardioverting Atrial Fibrillation by Anders Sjørslev Schmidt et al. published in the Circulation.
https://doi.org/10.1161/CIRCULATIONAHA.121.056301