Serial evaluation of atrial function by Doppler echocardiography after the maze procedure for chronic atrial fibrillation

Abstract
The primary goal of the maze procedure is to prevent thromboembolism by restoring atrial function. We used Doppler echocardiography to evaluate the atrial function of patients who had undergone the maze procedure for the treatment of chronic atrial fibrillation. Thirty-five patients who converted to sinus rhythm after the maze procedure were enrolled in this study. Doppler echocardiography was performed in all patients in the early (mean, 19 days) and late (mean, 245 days) phases of the postoperative period. Left and right atrial active contraction fractions and left and right atrial storage fractions were calculated. The relationship between the pre-operative left atrial dimension and the left atrial active contraction fraction was evaluated in the late postoperative phase. The left atrial active contraction fraction was significantly increased in the late phase, but there was no change in the left atrial storage fraction. While the right atrial storage fraction was improved in the late phase, the right atrial active contraction fraction was increased even in the early phase. In patients with non-rheumatic mitral valve disease, a significant negative correlation was observed between the pre-operative left atrial dimension and the left atrial active contraction fraction in the late postoperative phase (r=0·61; P<0·05). However, no correlation between these parameters was observed in patients with rheumatic mitral valve disease. Atrial function was improved after the maze procedure. Serial differences were observed between left and right atrial function during recovery. Thus, in patients with non-rheumatic mitral valve disease, the left atrial dimension prior to the maze procedure may be useful in predicting the atrial contractile function postoperatively.