Impairment of the myocardial ultrastructure and changes of the cytoskeleton in dilated cardiomyopathy

J Schaper, R Froede, S Hein, A Buck, H Hashizume, B Speiser, A Friedl, N Bleese
1991 Circulation  
This study was designed to determine the morphological correlate of chronic heart failure. Myocardial tissue from eight patients undergoing transplantation surgery because of end-stage dilated cardiomyopathy was investigated by electron microscopy and immunocytochemistry using monoclonal antibodies against elements of the cytoskeleton: desmin, tubulin, vinculin, and vimentin. The tissue showed hypertrophy, atrophy of myocytes, and an increased amount of fibrosis. Ultrastructural changes
more » ... ral changes consisted of enlargement and varying shape of nuclei, numerous very small mitochondria, proliferation of T tubules, and accumulation of lipid droplets and glycogen. The most obvious ultrastructural alteration was the decrease of myofilaments, ranging from rarefication to complete absence of sarcomeres in cells filled with unspecified cytoplasm. Immunocytochemistry showed that desmin was localized at the Z lines. In diseased myocardium, the amount of desmin was increased, but it was disorderly arranged. Tubulin formed a fine network throughout the myocytes and was significantly increased in cardiomyopathic hearts. Vinculin, a protein closely associated with the cytoskeleton, occurred not only at the sarcolemma and the intercalated disc but also within the myocardial cells. Ultrastructural changes and alterations of the cytoskeleton were severe in about one third of all cells. About one third of all cells showed moderately severe changes, and the remaining cells were normal. Vimentin was present in the interstitial cells and was increased in relation to the increase of fibrosis. We conclude that the increase of fibrosis, the degeneration of hypertrophied myocardial cells, and the alterations of the cytoskeleton are the morphological correlates of reduced myocardial function in chronic heart failure. (Circulation 1991:83:504-514) P atients with chronic dilated and progressive cardiomyopathy exhibit severe heart failure in the late stage of the disease. These patients show a decreasing left ventricular ejection fraction; they are in New York Heart Association functional stage IV; and despite drug treatment, they will die of congestive heart failure unless treated with transplantation surgery. Morphological cellular changes in chronic heart failure due to dilated cardiomyopathy have not yet been systematically described. However, several ultrastructural studies on catheter biopsy material removed from human hearts at various stages of this
doi:10.1161/01.cir.83.2.504 pmid:1991369 fatcat:guwgz4gl6vaqxp6exd2muquf4q