A wide variety of non-pulmonary manifestations of a coronavirus disease 2019 (COVID-19) has enriched clinical performance of cardiac diseases with atypical symptoms. Two COVID-19 cases are presented, where sinus bradycardia and syncope, which are rare in COVID-19, were the leading ones after the infection. The patients had no prior cardiovascular diseases, while the examination did not detected neurological pathology and myocarditis. Echocardiography showed relatively small pericardial effusion, which is supposed to be a cause of the symptoms as the diagnosis to exclude. A local buildup of inflammatory fluid around the sinus node and extensive ganglion plexuses around the atria can possibly affect the automatism and chronotropic compensation in addition to the myocardial inflammation. As part of the treatment against the hydropericardium syndrome, the symptoms disappeared, without reoccurring within subsequent 6-month follow-up. The third clinical case regards the pandemic outbreak, when we could not even suspect that the systemic inflammation would persist for many months after COVID-19 and radiofrequency ablation can lead to sudden cardiac death.

In an ever-changing information flow on coronavirus disease 2019 (COVID-19) pandemic, we describe a case series of mitral valve chordal rupture (MVCR) in non-comorbid middle-aged men that occurred over a period of 3 to 5 weeks after Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection. With significant advances in the prevention of acute rheumatic fever, the treatment of bacterial endocarditis and acute coronary syndrome, acute mitral regurgitation has become a relatively rare diagnosis. During the pandemic, there has been a surge in the incidence of spontaneous MVCR, and new data on the problem are accumulating. The presented case series are united by the fact that the infection symptoms were mild, followed by signs of probable endomyocarditis, unrecognized in time, and acute mitral valve regurgitation developed against the background of physical provocation (exercise and cough). Two patients had previously been diagnosed with mitral valve prolapse (myxomatous degeneration and connective tissue disease). Two patients were successfully operated on in different clinics. The described cases emphasize that the consequences of inflammation persistence may be more severe than the primary viral damage, which determines the importance of a comprehensive examination and long-term follow-up. To date, the differential diagnosis of patients with sudden onset of dyspnea and chest pain associated with an infectious process should include MVCR.

The article provides a review of scientifi c publications dedicated to the study of the hemostatic system in patients with chronic heart failure (CHF). Russian and foreign authors evaluated the risks of bleeding and thrombosis in patients with CHF, as well as changes in the content of individual markers and factors of the coagulation system. The review suggests that the results obtained are quite contradictory. On the one hand, data is presented on an increased risk of thrombosis, changes in the content of some endothelial markers that promote endothelial thrombogenicity, an increase in the content of platelet aggregation markers, and elevated levels of fi brinogen and thrombin. On the other hand, there is data on an increased risk of bleeding in patients with CHF, an increase in some endothelial markers that enhance the anticoagulant properties of the endothelium. From the analysis conducted, it can be concluded that this topic is not suffi  ciently studied, and it is diffi  cult to judge the hemostatic potential in patients with CHF at present. The use of integrated methods such as thromboelastography (TEG) and low-frequency piezothromboelastography (LF-PTEG) are a promising direction for studying this problem. The results obtained using these methods will likely allow for a more precise understanding of the features of the coagulation system functioning in patients with CHF.

The opinion that COVID-19 is a greater threat only to the elderly people has changed over the past year. Experience has been accumulated in the development of complications of varying severity in young patients who had optimal health indicators before infection. The consequences of myocarditis are most dangerous, especially in athletes and military personnel. We present a series of clinical cases of spontaneous mitral valve chordae rupture in highly trained middle-aged men in the early post-COVID period. In all cases, the infection proceeded subclinically; SARS-CoV-2 was verified only by analysis for IgM. 1–2 weeks after infection, against the background of a routine training process, patients felt pain in the heart area, which was underestimated. Patients presented for help at 2 and 10 weeks with complaints of reduced endurance and shortness of breath. Echocardiography revealed rupture of one of the chords of the anterior part of the mitral valve against the background of signs of myocarditis with the development of valvular insufficiency of the 1st degree. By the time of treatment, the pathology of other laboratory data and ECG was not observed. The control after 6 months showed in 1 patient a focus of myocardial fibrosis according to MRI, a minimal increase in NT-proBNP, a decrease in exercise tolerance, in 2 patients there was no visible fibrosis, normal NT-proBNP and complete restoration of exercise tolerance, but a decrease in local myocardial deformation according to echocardiography.