Sinus Rhythm Maintenance After Electrical Cardioversion for Atrial Fibrillation in High-Risk Patients — Comparative Efficacy of Antiarrhythmic Medications

Atrial fibrillation (AF) conversion to sinus rhythm by electrical cardioversion (ECV) is followed by the challenge of preventing arrhythmia recurrence, especially in high-risk patients. The properties of class IC, class III and also class II antiarrhythmic medications have been established, but not all effects have been studied. The aim of the study was to compare efficacy of class IC and class III antiarrhythmic medications, and additionally medication with a class II mechanism of action, or taken concomitantly with a beta-blocker, for post-cardioversion sinus rhythm maintenance in patients with high-risk AF. A total of 112 patients who underwent successful ECV in Latvian Centre of Cardiology were included. Data was acquired by a face-to-face interview and 1-, 3-, 6-month follow-up interviews. Comparing class IC (used by 34.8%) and class III (used by 65.2%) drugs, there was no statistically significant difference between six-month sinus rhythm maintenance rates (53.8% vs. 63.0%, p = 0.346) and arrhythmia-free survival (p = 0.313). Comparing amiodarone (used by 57.1%) and ethacizine, concurrently with a beta-blocker (used by 25.9%), no statistically significant difference was found between six-month sinus rhythm maintenance (64.1% vs. 58.6%, p = 0.616) and arrhythmia-free survival (p = 0.706). The results showed that specific antiarrhythmic drug choice was not associated with superior effectiveness, highlighting that, if not contraindicated, ethacizine, concomitantly with a beta-blocker, could be used as a similarly effective alternative for amiodarone, which has adverse health effects.