Aim Dynamic assessment of the right heart in patients with COVID-19-associated pneumonia of different severity during regression of the systemic inflammatory response (SIR).Material an methods This single-center prospective study included 46 patients with the novel coronavirus infection COVID-19 and viral pneumonia according to chest multispiral computed tomography (CT). Laboratory and echocardiographic examinations of patients were performed.Results Based on the results of evaluation with the Clinical Condition Scale (CCS-COVID), patients were divided into two groups: group A, patients with a score from 6 to 9 and group B, patients with a score from 10 to 14. The study results of both groups were evaluated twice: on day 10±2.5 from the onset of symptoms (groups A10 and B10, respectively) and again on day 17±1.8 (groups A17 and B17, respectively). Patients of group B10 had more pronounced SIR (C-reactive protein, 111.38±52.5 mg / l) and a larger volume of ground-glass opacity (38.3±9.6 %). At the first stage, higher values of right ventricular global longitudinal strain (RV GLS) were detected in group B10 compared to group A10 (23.2±4.8 % vs. 19.9±3.5 %, р=0.048). During the regression of SIR intensity and the positive dynamics of CT, lower values of Е / А were observed in group B17 (1.0 [0.98; 1.2]) vs. group А17 (1.4 [1.18; 1.5, p=0.015), and е' / a' in group B17 (0.66 [0.58; 0.85]) vs. 0.95 [0.79; 1.12] in group B17 (p=0.010). Е / А and е' / a' ratios were correlated with total lactate dehydrogenase fraction (r= -0.452 and p=0.006; r= -0.334 and p=0.050, respectively).Conclusion In patients with severe COVID-19-associated pneumonia during regression of SIR intensity, changes in the parameters that reflected RV diastolic dysfunction were observed.