LIGHT-AND ELECTRON-MICRTSCOPIC FINDINGS OF MYOCARDIAL BIOPSIES IN CARDIOMYOPATHY

Abstract

Right ventricular endomyocardial biopsies were performed in 34 patients with hypertrophic cardiomyopathy (HCM) and in 26 with dilated cardiomyopathy (DCM). The degree of myocardial interstitial fibrosis and that of myocardial fiber disarray were assessed from light-microscopic samples. Cell diameters were measured from the light-microscopic samples. For electron-microscopic investigation, a semiquantitative score system derived from Sekiguchi was used. The following results were obtained.1) Interstitial fibrosis was more prominent in DCM, while myocardial fiber disarray was more so in HCM.2) There was no correlation between myocardial cell diameter and ultrastructural alterations in HCM and DCM.3) In HCM, myocardial fiber disarray was correlated with ultrastructural alterations.4) In DCM, the left ventricular ejection fraction was negatively correlated with ultrastructural alterations.5) In HCM, there was no correration between interventricular septal thickness and myocardial cell diameter.