Safety and efficacy of electric cardioversion in the emergency department: analysis of associated factors according to gender.

Objective: To explore the safety and effectiveness of electric cardioversion to treat atrial fibrillation in a hospital emergency department (ED).
Methods: Retrospective observational study in a hospital ED. We reviewed episodes of atrial fibrillation in patients aged 18 years orolder treated with cardioversion in our ED or referred for scheduling of cardioversion. Clinical outcome measures were conversion to sinus rhythm, immediate adverse effects (hypotension, arrythmia, or bronchial aspiration), revisiting within 90 days for atrial fibrillation, and complications (stroke, major bleeding, heart failure, or death). We studied factors associated with recurrence and adverse effects according to sex.
Results: Cardioversion was used in 365 episodes (median patient age, 67 years); 38.6% were women. Cardioversion was applied in the ED in 75.1% of the episodes, and 24.9% were referred for scheduled cardioversion. Sinus rhythm was restored in 90.7% of the episodes. Emergency cardioversion was more effective than a scheduled procedure (odds ratio [OR], 4.258; 95% CI, 2.046-8.859; P < .001). No serious immediate adverse effects were reported, but 16.7% of the patients revisited for atrial fibrillation within 90 days. Factors associated with revisits were heart failure (hazard ratio [HR], 2.603; 95% CI, 1.298-5.222; P = .007), sleep apnea (HR, 2.598; 95% CI, 1.163-5.803; P = .020), and, in women, hypertension (HR, 3.706; 95% CI, 1.051-13.068; P = .042). Eleven patients developed late adverse events, including stroke (n = 2), major bleeding (n = 1), heart failure (n = 5), and death (n = 3).
Conclusions: Cardioversion is a useful, effective, and safe treatment for atrial fibrillation in the ED, although there are frequent recurrences. Factors associated with recurrence differ according to sex.