Left ventricular function after mitral valve operation in congenital mitral regurgitation

ABSTRACT

BACKGROUND: Severe mitral regurgitation is a common clinical entity that can lead to progressive, irreversible left ventricular dysfunction, and thus should be corrected in proper stage of life. Authors have conducted this investigation to assess left ventricular function after mitral valve operation and to determine the predicting factors. METHODS AND RESULTS: The echocardiographic parameters, specifically left ventricular ejection fraction, shortening fraction, end-systolic dimension and volume, and end-diastolic dimension and volume were measured in preoperative and postoperative period of congenital mitral regurgitation patients (n=60), between March 1992 and March 1998. After correction of severe mitral regurgitaion, left ventricular ejection fraction and shortening fraction decreased significantly (p<0.001 and p<0.05 respectively). Furtheremore, after reoperation of recurred mitral regurgitation, left ventricular ejection fraction and shortening fraction decreased significantly (p<0.05). Left ventricular ejection fraction and shortening fraction in mitral valve reoperation group (n=23) is significantly lower than those in non-reoperation group (n=37) in both preoperative and postoperative period (p<0.05). Left ventricular ejection fraction and shortening fraction is also significantly lower in mitral valve replacement group (n=20) than in mitral valvuloplasty group (n=40)(p<0.05). Severe postoperative left ventricular dysfunction led to dilated cardiomyopathy in 5 patients. Postoperative left ventricular end systolic dimension increased significantly in reoperation group and DCMP group respectively (p<0.05). CONCLUSION: After surgical correction of mitral regurgitation, left ventricular dysfunction is frequent and carries a poor prognosis. Postoperative left ventricular dysfunction can be predicted by preoperative ejection fraction, shortening fraction and systolic diameter. Therefore surgical therapy before the onset of left ventricular dysfunction is recommended.