BACKGROUND Factors predicting the maintenance of sinus rhythm (SR) after cardioversion of atrial fibrillation (AF) have not been well defined. Little is known about the impact of the recovery of the left atrial mechanical function (RLAMF) on AF recurrences. OBJECTIVE To identify the clinical and echocardiographic predictors of AF recurrences after cardioversion. METHODS Of 112 consecutive patients (39 females, 73 males, mean age 62.1+/-10.6 years) with AF who underwent successful electrical or pharmacological cardioversion, 50 maintained SR during 6 month follow-up whereas the remaining 62 had a recurrence of AF. Clinical examination and 2D Doppler echocardiography were performed. From the Doppler mitral flow, RLAMF was evaluated 1, 7, and 21 days after cardioversion. RESULTS Patients with or without AF recurrence did not differ with respect to age, gender, aetiology, duration of AF, LA size and ejection fraction. In the univariate analysis the lack of RLAMF detected 1 day after cardioversion (relative risk - RR=1.15, p<0.01), functional NYHA class II or III (RR=1.86, p<0.005) and a history of AF episodes (RR=2.02, p</=0.0005) were identified as the predictors of a recurrence of AF. In the multivariate analysis using Cox proportional hazard model the latter two factors remained the independent predictors of AF recurrences during a six-month follow-up period. The Kaplan-Meier analysis showed that out of all analysed risk factors, the most significant were functional NYHA class, history of AF and lack of RLAMF one day after cardioversion. CONCLUSIONS A history of AF, functional NYHA class II or III, and the lack of RLAMF were the independent predictors of a recurrence of AF. The presence of more than one risk factor strongly identified those who failed to maintain SR during six-month follow-up.