Laboratory-instrumental and histological data characteristic of myocardial changes in COVID-19

The nature and mechanisms of damage to organs and tissues during SARS-Cov-2 infection in certain areas remain unclear over the past 2 years. Material and methods . The study included 70 patients who underwent COVID-19 and were divided into 4 groups depending on the volume of lung damage according to the results of computed tomography. Assessment of echocardiographic parameters of longitudinal myocardial deformation (speckle-tracking) was performed on the 25–40th day of diagnosis using the GE Vivid S70 device. The histological picture of changes in the myocardium is given taking into account 30 protocols of autopsy of patients with severe and extremely severe course of the disease. Results . Myocardial damage in the form of a violation of the longitudinal strain index (as an indirect sign of myocarditis in a number of patients, but not in those with COVID-19) was most often (in 83% of cases) recorded in the CT-3 group with a lung lesion volume of 51–75%. A nonspecific histological picture in the form of edema of myofibrils, pallor of the nuclei, edema of the sarcoplasm, dystrophic changes clearly cannot be interpreted as myocarditis, and such a diagnosis has never been made, especially coronavirus. Hypertrophy of cardiomyocytes indicates the presence of chronic hypoxia, ischemia, metabolic changes (to a greater extent as a background from concomitant pathology — diabetes mellitus, hypertension, coronary artery disease). None of the examined patients who underwent an immunological blood test for the presence of “antibodies to the myocardium” were found to have such. Conclusion . Taking into account the data obtained, we can only talk about non-specific changes in organs and tissues against the background of COVID-19, including in the myocardium. However, myocarditis was not verified in any of the cases.