to determine which changes of cardiovascular system clinical, and structural, and functional state in emergency workers (EW) of the accident at the Chornobyl nuclear power plant (CNNP) can be associated with COVID-19 they suffered from and not with the natural progression of coronary heart disease (CHD).
The study included 16 male EW who fell ill with mild and medium-severe COVID-19 (EWC group) in 2020-2021, which was confirmed by a PCR test (polymerase chain reaction). All these patients were observed in the NRCRM cardiology department before infection with the coronavirus. The comparison group consisted of 32 EW who did not suffer from COVID-19 and their age and examination dates corresponded to EWC. General clinical, laboratory, statistical methods and Doppler echocardiography were used for patients examination.
In the post-covid period, EW-C observed a worsening of CHD clinical course, which consisted in an increase in the number of patients with severe functional class angina pectoris, with ventricular and supraventricular extrasystoles, as well as with more severe heart failure (HF). Since similar changes in the state of the cardiovascular system were found among EW who did not suffer from COVID-19, they can be attributed to the natural progression of CHD. In the EW-C group, there was an increase in the number of patients with atrial fibrillation (AF) by 4 times (up 37.5 %), while in the comparison group EW only by 1.1 times (up 3.1 %). The progression of CHD and HF in the examined patients was accompanied by an increase in the end-diastolic and end-systolic volumes of the left ventricle and the mass of the myocardium, the severity of which was not significantly different in patients with and without COVID-19. The number of post-covid patients with reduced ejection fraction (EF) during examination after COVID-19 increased by 31.3 %, and in the group of EW, which were examined at the same time, by 6.32 %.
A significant increase in the number of patients with AF and a reduced EF in the EW-C compared with the EW can be attributed to the results of the SARS-CoV-2 virus influence on cardiovascular system.

D. Belyi, О. Nastina, G. Sydorenko, N. Kursina, O. Bazyka, O. Kovaliov, D. Bazyka.