Left ventricular function in rheumatic mitral stenosis. Clinical echocardiographic study.

Echocardiography was used to examine the extent and significance of impairment in left ventricular function in 20 patients with rheumatic mitral stenosis. Indices of left ventricular performance--normalised mean rate of circumferential fibre shortening (Vcf), ejection fraction, normalised posterior wall velocity, and stroke volume were reduced. The impairment in left ventricular function was related to the degree of functional disability (NYHA), right ventricular dilatation, and left atrial enlargement. Vcf was inversely related to both the internal right ventricular diameter (r=-0.767, P less than 0.001) and the degree of left atrial enlargement (r=-0.554; P less than 0.05). The normalised velocity of the interventricular septum and the maximum systolic and diastolic endocardial velocities were also reduced. These results suggest that abnormalities in contractility of left ventricular myocardium are responsible for the impaired myocardial function in patients with mitral stenosis and that such impairment is clinically significant.