Long-term follow-up of atrial contraction after the maze procedure in patients with mitral valve disease

OBJECTIVES We sought to determine the effectiveness of the maze procedure for maintaining sinus rhythm and atrial contraction for a long period in patients with mitral valve disease. BACKGROUND Although the maze procedure for atrial fibrillation (AF) has been effective in restoring sinus rhythm in patients with mitral valve disease, the long-term results of this procedure have not been determined. METHODS We echocardiographically studied 94 consecutive patients with mitral valve disease before, as well as early (3.1 ± 3.3 months) and late (2.2 ± 0.9 years) after, the maze procedure. Peak velocity and the time-velocity integral of the left ventricular (LV) diastolic filling wave during atrial contraction (A wave), as well as the atrial filling fraction (calculated as the ratio of the time-velocity integral of the A wave to total diastolic filling), were obtained from transmitral flow recordings. Peak A wave velocity ≥10 cm/s was considered to indicate echocardiographic evidence of effective atrial contraction. RESULTS Regular rhythm with P waves was restored in 70 patients (74%) in the early stage and in 59 patients (63%, P = 0.09) in the late stage after the maze procedure. Forty-seven patients (50%) in the early stage and 36 patients (38%, P = 0.14) in the late stage showed effective atrial contraction by Doppler echocardiography. Left atrial (LA) and LV end-diastolic diameters significantly decreased after the procedure (from 59 ± 13 to 48 ± 7 mm, p < 0.01; and from 54 ± 9 to 47 ± 5 mm, p < 0.01, respectively) and did not show significant changes during the follow-up period. Once atrial contraction was resumed, its degree did not change between the early and late stages after the maze procedure (17 ± 6% vs. 17 ± 6% for atrial filling fraction). CONCLUSIONS Sinus rhythm and atrial contraction recovered early after the maze procedure in most patients and were maintained for more than two years. Once active atrial contraction was resumed, the degree of contraction did not change thereafter. These results demonstrate that the maze procedure is effective for a long period in patients with mitral valve disease.