Histopathological studies on the myocardial fibrosis and vascular lesion of rheumatic valvular disease.

Abstract

To clarify the types and frequency of myocardial fibrosis and vascular lesions caused by different types of the rheumatic valvular disease, 41 autopsied hearts with rheumatic valvular lesions were examined and the following results were obtained. As to myocardial fibrosis, 1) perivascular fibrosis, caused mainly by perivascular inflammation and partly by myocardial strain, varied in grade according to the types of the valvular disease, i.e., most severe in mitral regurgitation (MR) and combined valvular disease (CVD) and least in mitral stenosis (MS); 2) Aschoff's nodes: 3 typical and 8 atypical cases were found; 3) perimycial fibrosis due to myocardial strain: most severe in MR and CVD and least in MS; and 4) irregular patchy fibrosis, caused mainly by myocarditis and partly by ischemia, was noticed in all types of the valvular disease. As to vascular lesion, 1) angitis was found in 7 cases and most frequently in MR; and 2) thickening of the intima and media was found in all types of valvular disease. Thus, myocardial fibrosis and vascular lesion varied according to the types of valvular disease, and not only hemodynamic changes but also myocardial fibrosis and vascular lesions might determine the prognosis of the valvular disease.