[The causes and management of ischemic mitral regurgitation]

Ischemic mitral regurgitation (IMR) is recognized as one of the complications of coronary artery disease. The aim of this study is to evaluate the causes and surgical management of IMR. From October 1986 to March 1995, 443 of patients underwent isolated coronary artery bypass grafting (CABG). In forty-four of the patients (9.9%) who underwent isolated CABG, the severity of postoperative IMR was reduced by two or more grades by the Sellers index. Hemodynamic parameters of these patients included: left ventricle ejection fraction, left ventricle end-diastolic volume index and left ventricle regional wall motion. They were assessed by left ventriculography (LVG). In addition, cardiac index and pulmonary artery wedge pressure were assessed by S-G catheterization and mitral annulus diameter by ultrasonic echocardiography. Twenty-nine patients experienced an increase in IMR severity after CABG, one of whom required mitral valve replacement for cardiac failure, and later died due to low output syndrome postoperative. On the other hand, fifteen patients experience a reduction in IMR severity after CABG. We conclude that the causes of IMR were regional asynergy at the site of papillary muscle, mitral annulus dilation and left ventricle dilation. Our findings suggest that severe IMR patients required concomitant mitral valve surgery with CABG. Patients with mild or moderate IMR patients with mitral annulus dilation or regional asynergy at the site of mitral papillary muscle may require the same surgery.