[Restoring the mechanical atrial function after cardioversion of atrial fibrillation: clinical and echocardiographic predictive factors].

BACKGROUND: A delay in the recovery of effective mechanical atrial function after cardioversion for atrial fibrillation can predispose to thromboembolism. The aim of the present study was to assess the influence of clinical and echocardiographic parameters on the recovery of left atrial contraction after cardioversion of atrial fibrillation. METHODS: One hundred and 36 consecutive patients were evaluated and 80 were randomly cardioverted using either DC shock or i.v. procainamide. Patients who recovered sinus rhythm (26 patients treated with procainamide and 39 patients cardioverted with DC shock) underwent a complete Doppler echocardiographic examination 1 hour after the restoration of sinus rhythm and after 1 and 7 days and 1, 3, and 6 months. The following parameters were evaluated: age, underlying cardiac disease, duration and etiology of atrial fibrillation, mode of cardioversion, left ventricular diameters and function, left atrial diameters and function, assessed as atrial ejection force. The relation between these variables and atrial ejection force was tested. RESULTS: Atrial ejection force was greater immediately and at 24 hours after cardioversion in patients who underwent pharmacological therapy compared to patients treated with DC shock. In all groups atrial ejection force increased over time. The mode of cardioversion was significantly associated with the recovery of left atrial mechanical function by day 1 in univariate and multivariate analyses (odds ratio 0.14, 95% confidence interval 0.03-1.6). The other variable associated with atrial ejection force was left atrial size (odds ratio 0.15, 95% confidence interval 0.17-1.9). CONCLUSIONS: Atrial ejection force can be easily measured after cardioversion to obtain accurate information about the recovery of left atrial mechanical function. In the present study the recovery of left atrial function was influenced by the mode of cardioversion and left atrial size.