Background: Many studies have tried to propose risk factors for atrial fibrillation recurrence after a successful pharmacological or electrical cardioversion. Regarding the duration of atrial fibrillation before electrical cardioversion, only limited data exist. The aim of our study was to investigate the effect of atrial fibrillation duration on long-term sinus rhythm maintenance in patients after successful electrical cardioversion of persistent atrial fibrillation.
Material/Methods: Three hundred one patients after successful electrical cardioversion were included in the analysis. The patients were followed for 2 years. Electrocardiogram showing atrial fibrillation was considered the study endpoint.
Results: After mean observational time of 377±311 days, atrial fibrillation occurred in 168 patients (61.5%). Multivariate logistic regression analysis showed the duration of atrial fibrillation was the only predictor of atrial fibrillation recurrence (OR 1.06; CI 1.00–1.11; P=.036), while amiodarone appeared to protect against atrial fibrillation recurrence OR 0.26; CI 0.07–0.95; P=.041). A Cox proportional hazards multivariate model predicted atrial fibrillation recurrence rate of atrial fibrillation ≥10 months (OR 1.87, CI 1.26 to 2.76, P=.002) and treatment with amiodarone (OR 0.55, CI 0.40–0.76, P=.000).
Conclusions: Atrial fibrillation duration before electric cardioversion is a significant predictor of atrial fibrillation recurrence rate after successful restoration of sinus rhythm. Further studies are needed to clarify the implications of atrial fibrillation duration on sinus rhythm persistence after a successful cardioversion.

Keywords: Proportional Hazards Models, Predictive Value of Tests, Logistic Models, Electrocardiography, Electric Countershock, Atrial Fibrillation - therapy, Anti-Arrhythmia Agents - therapeutic use, Amiodarone - therapeutic use, Recurrence - prevention & control, Risk Factors, Time Factors