MORPHOLOGICAL MANIFESTATIONS OF MYOCARDIAL LESION IN COVID-19

Abstract

To date, the pathogenesis and morphogenesis of COVID-19 have not been studied in depth, and therefore, in this work, the goal is to study the damage to the parenchymal-stromal elements of the myocardium in COVID-19. The material for the study was pieces from the myocardium of the ventricular wall of 26 patients who died from COVID-19 at the age of 28 to 56 years. The results of a morphological study showed that edema and mucoid swelling of the interstitial tissue of the myocardium in COVID-19 occurs due to the accumulation of hyaluronan, the development of dystrophy, dysregeneration and inflammation of blood vessels and connective tissue structures. In the myocardial parenchyma, contracture disorders, homogeneous compaction of the cytoplasm of cardiomyocytes, disappearance of the transverse striation of myofibrils, focal development of basophilia, PAS-positive metaplasia of cardiomyocytes, fragmentation, degeneration and necrobiosis of muscle fibers were noted; compaction, deformation and destruction of the nuclei of cardiomyocytes. Injuries to cardiomyocytes are first manifested by sarcoplasm vacuolization, a change in the coloration and shape of the nucleus, then enlargement and hyperchromasia of the nucleus in the form of dysplasia occur, homogenization, metachromasia and blue staining are noted from the sarcoplasm, followed by lysis of the nucleus; in the future, metachromasia covers the entire cytoplasm of the cardiomyocyte and the cell dies.