[Electrode position in elective electrical cardioversion of atrial fibrillation. A randomized study]

Abstract

Aim: To compare the effectiveness of left anteroposterior (A-P) and apex-anterior (A-A) electrode position in the electrical cardioversion (ECV) of patients with atrial fibrillation (AF).

Design: Randomized clinical trial.

Location: ICU of a second-level hospital.

Patients and methods: Ambulatory AF patients admitted to ICU for ECV with biphasic shocks. Up to a maximum of 3 shocks (150-200-200 J) are given in the electrode position determined by random numbers, and if sinus rhythm (SR) is not restored, electrode position is changed and 2 additional 200 J shocks are allowed. Both electrode positions are analyzed and compared to determine which one allows restoration of SR with the lowest number of shocks and least energy.

Results: Forty-six patients were included in the A-A group, and 45 in the A-P group. Sinus rhythm was restored in 92% of cases, although patients in the A-A group needed a lower number of shocks and less energy: 1 versus 2 shocks (p=0,003) and 150 versus 350 J (p=0.017). Only one out of 5 patients in whom the A-A position had failed was reverted to RS with the A-P position, whereas 10 out of 13 patients in which A-P position had failed were reverted in the A-A position (p=0.038).

Conclusions: The A-A position is more effective in the elective electrical cardioversion of atrial fibrillation, so we recommend this position as the first choice.