This study aimed to investigate the features of the clinical course of COVID-19 in combination with the pathology of the cardiovascular system (CVS). A prospective study was carried out. The main group (n=150) consisted of patients with changes in the cardiovascular system associated with COVID-19, i.e. newly diagnosed CV pathology, and patients with exacerbation of cardiac pathology against the background of COVID-19. The comparison group (n=154) included patients with COVID-19, but without any significant concomitant cardiac pathology. The average age of patients in the main group was 67.7 years (from 47 to 86 years), in the comparison group of 66.1 years (from 48 to 88 years). The study groups were representative and did not differ statistically in the nature of COVID-19 symptoms and the degree of lung involvement. Among the cardiac pathology, progressing or first occurring against the background of infection with COVID-19, in most cases, arterial hypertension of II-III degree (60.0%), coronary heart disease (48.7%), arrhythmias (23.3%) were diagnosed. Echocardiographic abnormalities included right ventricular dysfunction (22.7%), left ventricular contractility disorders (18.7%), with decreased ejection fraction (17.3%), diastolic dysfunction (14.0%), and toxic myocarditis (7.3%). The most significant risk factors were the presence of a burdened medical history (RR=10.39), elevated body mass index over 30 (RR=2.63) and diabetes mellitus (RR=1.55). In patients with COVID-19 in combination with CVS pathology, a relatively high incidence of acute onset (64.0% vs. 44.2%; p<0.001), respiratory failure (83.7% vs. 62.0%; p<0.001), admission to the intensive care unit (25.3% vs. 11.7%; p=0.004), development of acute respiratory distress syndrome (20.0% vs. 9.1%; p=0.012), hospital mortality (10.7% vs. 2.7%; p=0.006). Cardiac manifestations of COVID-19 included focal or global myocardial inflammation, ventricular dysfunction, heart failure, and arrhythmias. A high frequency of acute onset of the disease, respiratory failure and hospital mortality is determined.