Echocardiography provides the evidence of mitral valve thickening, mitral valve regurgitation, left atrial and ventricular chamber enlargement. The severity of mitral valve regurgitation can be assessed by determining the regurgitant jet flow in the left atrium with color-Doppler mapping (Pedersen et al.,1999). The anterior leaflet or septal leaflet is more prone to degeneration. Therefore, the thickened and irregular anterior leaflet is easy to see by echocardiography. The disease progression can be determined by left atrial enlargement and left ventricular systolic dysfunction secondary to chronic volume overload resulting from mitral valve regurgitation. The systolic function of left ventricle is easily evaluated by calculating the fractional shortening and measuring the size of end systolic left ventricular dimension. The percentage of fractional shortening is the difference between the end-diastolic and end-systolic dimensions divided by the end-
diastolic dimension x100. Fractional shortening is preload dependent. It may be normal secondary to an increase of both end systolic and end diastolic chamber dimensions. Thus, it is better to determine systolic myocardial function by assessing the end systolic dimension or end systolic volume index also.