Doppler sonographic evaluation of left atrial function after cardioversion of atrial fibrillation

Restoration of sinus rhythm is not always followed by immediate return of effective atrial contraction. Left atrial mechanical function can be assessed by Doppler echocardiography; in the present study we measured the atrial ejection force, which is a noninvasive Doppler-derived parameter that measures the strength of atrial contraction. The aim of the present study was to evaluate the influence of clinical and echocardiographic parameters: duration and cause of atrial fibrillation, different modality of cardioversion, and left atrial size with respect to the delay in the return of effective atrial contraction after cardioversion. Seventy patients were randomly chosen to undergo cardioversion by either direct current shock or intravenously administered procainamide hydrochloride. The 52 patients who had sinus rhythm restored underwent a complete Doppler echocardiographic examination 1 h after the restoration of sinus rhythm and after 1 day, 7 days, and 1 month. The relation between clinical variables and atrial ejection force was tested. Atrial ejection force was greater immediately and 24 h after cardioversion in patients who underwent pharmacologic therapy compared to patients treated with direct current shock (11.3+/-3 versus 5+/-2.9 dynes; P<0.001). In both groups atrial ejection force increased over time. The mode of cardioversion was significantly associated with recovery of left atrial mechanical function by day 1 in univariate and multivariate analysis (odds ratio, 0.14; 95% confidence interval, 0.02-1.2). The other variable associated with the delay in the recovery of atrial function was a dilated left atrium (odds ratio, 0.16; 95% confidence interval, 0.12-1.6). Atrial ejection force is a noninvasive parameter that can be easily measured after cardioversion and gives accurate information about the recovery of left atrial mechanical function. The recovery of left atrial function was influenced by the mode of cardioversion and left atrial size.