The Purpose of this study was to investigate the clinical characteristics of the patients who underwent mitral valve repair and the effects of surgery on left ventricular ejection fraction(LVEF) and left ventricular dimension and to investigate the causes of degenerative mitral regurgitation(MR), the sites of valve lesion and the accuracy of preoperative TTE and TEE.

Patients who underwent mitral valve repair from January 1997 to December 2000 were studied retrospectively. Patients who underwent echocardiography before and immediately after the surgery, and follow-up study at least 1 year later were selected for the analysis.

The causes of mitral regurgitation were degenerative in 78 patients, rheumatic in 21, infective in 11, congenital in 10 and ischemic in 1. Left ventricular ejection fraction decreased significantly immediately after the surgery, but in increased thereafter significantly on follow-up study. Left ventricular diastolic and systolic dimension, and left atrial dimension decreased immediately after surgery and left ventricular systolic dimension decreased further on follow-up study. Patients with left ventricular dysfucntion(EF<45%) preoperatively showed no improvement in immediate post-operative and follow-up echocardiography(EF=40±9.1%, 39±13.9%, 40±10.8%, p=NS). The causes of degenerative MR were ruptured chordae in 52 patients, elongated chordae in 17,mitral valve prolapse without chordal involvement in 6, and ruptured and elongated chordae in 3. The lesions were in anterior leaflet in 36 patient(A1:12, A2:8, A3:2, A1+A2:10, A2+A3:4), posterior leaflet in 40 patients(P1:4, P2:9, P3:18, P1+P2:3, P1+P3:1, P2+P3:5) and both leaflets in 2 patients. TTE and TEE detected the location of the lesion in 85%, and 92%, respectively.

The most common cause of MR was degenerative. Mitral valve repair surgery should be done before LV dysfuction develpes, The most common cause of degenerative MR was chordal rupture and the most common site of valve lesion was P3. Echocardiography was very useful in mitral valve repair surgery.