Comparative Efficacy of the Maze Procedure for Restoration of Atrial Contraction in Patients With and Without Giant Left Atrium Associated With Mitral Valve Disease

Objectives. We sought to determine the effectiveness of the maze procedure for restoring atrial contraction in patients with and without giant left atrium (GLA). Background. Although the maze procedure has been reported to be effective for refractory atrial fibrillation, it is unknown whether this procedure can restore effective atrial contraction in patients with GLA. Methods. Nineteen patients with and 32 patients without GL were studied with Doppler echocardiography before and after the maze procedure. Peak velocity and the time-velocity integral of the left ventricular diastolic filling wave during atrial contraction ( wave) and the atrial filling fraction calculated as the ratio of the time-velocity integral of the wave to that of total diastolic filling were compared between patients with and without GLA. peak wave velocity ≥10 cm/s was considered to indicate echocardiographic evidence of effective atrial contraction. Results. Regular rhythm with P waves was restored in 10 patients (53%) with and 26 (81%, p < 0.05) without GLA. Four patients (21%) with and 21 patients (66%, p < 0.01) without GL showed effective atrial contraction by echocardiography. Once atrial contraction was resumed, the degree of atrial contraction was comparable between patients with and without GL (17 ± 5% vs. 17 ± 4% for atrial filling fraction at 12 months, respectively). Conclusions. Although most patients without GL had restored atrial contraction by the maze procedure, it was resumed in fewer patients with GLA. However, once atrial contraction was resumed, the degree of atrial contraction was comparable between patients with and without GLA. Therefore, the maze procedure may be an option in selected patients with GLA.