[Quantitative study of myocardial pathological lesions in rheumatic mitral valve disease: correlations with changes...

Pathological lesions of left ventricular myocardium from 21 patients with predominant mitral stenosis (MS) and from 16 patients with predominant mitral regurgitation (MI) were studied quantitatively by means of image analysis system and light microscopic examination. Their correlations with changes of cardiac function after mitral valve replacement were also studied. The results showed that the percentage of the area of interstitial fibrosis (F%), the shortest diameter of myocardial fiber (SDMF) and endocardial thickness (ET) increased, and the inner diameter-out diameter ratio of intramyocardial arteries (Di/Do) decreased in 37 patients in various degrees. F%, Di/Do, SDMF and ET correlated with delta EF, delta FS, delta ESVI, postoperative dosage of dopamine, and duration of assisted respiration analysed respectively by linear regression. Multiple myocardial pathological lesions correlated strongly with delta EF analysed by multiple linear regression with multiple correlation coefficient of 0.803 in MS group (P less than 0.01) and 0.763 in MI group (P less than 0.05). These data suggest that multiple evaluation of myocardial pathological lesions plays an important role in predicting prognosis of mitral valve replacement. After operation mean delta EF and delta FS decreased, dosage of dopamine and duration of assisted respiration increased when the patient had two or more following criteria: 1. F% greater than 31%, 2. Di/Do less than 0.400, 3. SDMF greater than 16 microns, 4. ET greater than 326 microns.