Hemodynamic and clinical significances of atrial fibrillation, pulmonary vascular resistance and left ventricular function in rheumatic mitral stenosis.

Seventy-four patients with rheumatic mitral stenosis were catheterized and hemodynamic and clinical significances of atrial fibrillation, pulmonary vascular resistance and left ventricular function were studied. These data were also compared to those in the 6 control cases. In addition to the correlation of mitral valve area to the functional classification of patients, significance of atrial fibrillation was also demonstrated. Patients with this arrhythmia had lower cardiac index than those with regular sinus rhythm by approximately 20%, throughout the range of mitral valve area observed. The lower average cardiac index was associated with a higher average left ventricular end-diastolic pressure in cases with atrial fibrillation than in cases without the arrhythmia, in the face of similar average heart rate and average mitral valve area; Average pulmonary vascular resistance correlated to the functional classification, but its systematic influence on the relation between mitral valve area and cardiac index was not observed. Abnormalities of left ventricular function were suggested frequently by various combinations of abnormal values in end-diastolic pressure, end-diastolic volume, ejection fraction, angiographically-measured circumferential fiber shortening velocity (Vcf), and pressure-derived maximal contractile element velocity (Vmax). Patients with enlarged left ventricle had significantly lower average cardiac index than those with normal ventricular size.