Abstract
Polycythemia vera (PV) is an orphan haematological disease and one of the most common myeloproliferative diseases, with the incidence rate of about 0.4-2.8 cases per 100 000 population per year. In patients, proliferation of all three haematopoietic lineages is observed, typically with the development of erythrocytosis. As a rule, PV occurs in patients aged 60-70 years, slightly more often in men. The main clinical signs of PV are weakness, significant burning sensation in fingers and palms due to the increased blood viscosity and microcirculation disorders, discomfort in the left hypochondrium due to splenomegaly at the background of extramedullary haematopoietic sites development, as well as gross vascular complications (thrombosis) of various localisation. Our clinical case represents a rare cardiac manifestation of the PV in a young man.