Purpose. To identify the occurrence and structure of changes in the pericardium ultrasonography among patients who have undergone COVID-19 and have cardiological symptoms, as well as to compare these changes with the pericarditis aspects and the infection time duration in a prospective cohort observational study.

Methods. Inclusion/exclusion criteria: current or transferred COVID-19, new symptoms that occurred during or after infection and forced to consult a cardiologist, the absence of other prerequisites for pericarditis and vaccination against SARS-CoV-2. Echocardiography was performed with an emphasis on the pericardium and an assessment of the echogenicity amplification, the area of the hyperechoic zone, thickness and artifacts, as well as a questionnaire.

Results. From 05.2020 to On 10.2020, 335 patients from the covid ward and 284 patients from the out-patient clinic were included. 86% of patients had transient chest discomfort. The peaks of treatment accrued to 4-5 and 10-11 weeks (Me 10[2-36] (1 to 64) weeks) from SARS-CoV-2 infection occurred. Typical ECG changes were registered in 3%, pericardial friction noise – in 7% of patients. In 20% of patients discomfort in the heart area was the first, in 27% – the dominant, in 14% – the only symptom of COVID-19. According to EchoCG data, 96% of the examined patients had ultrasound signs of different changes in the pericardium: slight effusion in 65%, signs of tamponade in 2%, thickening in 12%, local hyperechogenicity in 83%, local adhesion in 8% of patients. The group without pericardial changes was distinguished by the presence of epicardial fat >7 mm. A combination of the echo-cardiography criteria with the second symptom recorded at the visit or earlier was present in 76% of the applicants. Comparison of the recorded ultrasound patterns with the time elapsed since infection allowed us to distinguish ultrasound phases: 1) the phase of damage (pattern of initial edema) occurred at 1 week, 2) the phase of edema /exudation (pattern of visible effusion) – at 3 weeks, 3) fibrosis (pattern of pericardial compaction) – at 11 weeks, 4) regression of inflammatory changes (pattern of local fibrin deposition) – on week 22, 5) residual signs of transferred inflammation may be visualized in patients with symptoms 44 weeks after COVID-19.

Conclusions. Consideration of the infectious process triggered by SARS-CoV-2, as a systemic inflammation, allows us to interpret the phenomenon of pericardial involvement as a reactive serositis having ultrasound phases. It was possible to trace some patterns of echocardiography at different stages of the infectious and post-infectious period. Clinical data of 76% of patients can be interpreted as pericarditis, changes in 20% – as an increase in echogenicity of the pericardium.