[Heart valves in rheumatic heart disease in the light of scanning electron microscopy].

In case of rheumatic sclerosis the micro-relief of the surface of the mitral and aortic valves changes considerably: the first order plicas disappear, a new chaotic micro-relief is formed that depends on the deep specific changes in the collagen-elastic structures of the valves. In rheumatic heart diseases the valves are characterized by focal disendothelization of the surface, which permits to examine the valve in layers, and to study not only its surface, but also its internal subendothelial structures. Scanning electron microscopy permitted to visualize for the first time in a full three-dimentional image the severely altered collagen structures of the disendothelialized portions of rhumatic valves. The changes in the micro-telief consisting in the appearance of amall, irregularly located plicas, crossing each other under various angles, are caused by the development of new subendothelial collagen fibers. The initial forms of calcification are characterized by the appearance of micro-plates of calcination in the zones of the destroyed micro-relief, the subsequent forms -- by the formation of large clusters of calcination due to the fusion of the micro-plates. The destroyed micro-relief of the valves causes the adhesion of erythrocytes on their surfaces, which may be considered a factor halping thrombus formation.