Evaluation of Specific Methods in Hemorheology and Angiology

Abstract

Hemorheology is the science of flow properties of blood and its elements. Clinical hemorheology describes the unique behavior of blood with such measurable parameters like hematocrit, plasma and whole blood viscosity, red blood cell aggregation and deformability. Numerous vascular, hematological and pulmonary diseases are associated with increased plasma (PV) and whole blood viscosity (WBV), both identified as primary cardiovascular risk factors as well as variables with prognostic significance in certain clinical conditions. The blood plasma behaves as a Newtonian fluid (its viscosity does not depend on shear rate) while the whole blood behaves as a non-Newtonian pseudoplastic fluid. WBV is an important determinant of blood flow resistance, its elevated level may cause a disturbance in tissue perfusion due to decreased flow rate. Plasma viscosity is an important factor of flow resistance in the microcirculation, mediating shear stress toward the endothelium as a consequence of the axial migration of RBCs, therefore it plays a role in the mechanism of vasodilation. The altered hemorheological variables in association with atherosclerosis are elevated plasma and whole blood viscosity, plasma fibrinogen concentration and impaired red blood cell deformability.