The development of the blood hyperviscosity syndrome in patients with a history of pulmonary artery thromboembolism

Examination of 64 patients with prior pulmonary artery thromboembolism revealed high blood viscosity in 88% of males and 77% of females. Polycythemia and disturbed erythrocyte deformability were the causes of increased blood viscosity. The degree of disturbed blood viscosity correlated with the degree of hemodynamic disorders. The development of the blood hyperviscosity syndrome was determined by the extent of the affected lungs rather than by the duration of the disease.