Importance of Blood Viscoelasticity in Arteriosclerosis

Abstract

Corpuscular and biochemical components of blood create the vis coelastic nature of blood flow, which varies because of changes in flow ve locity. The flow properties of blood are of special interest in arterioscle rotic diseases for vasoregulatory mechanisms are often disturbed in these states. The authors compared the rheologic properties of blood in patients with arteriosclerotic lesions (coronary heart disease: n=56; cere brovascular disease: n=37; periph eral arterial occlusive disease: n=29 and healthy controls: n=42). With a new oscillating capillary rheometer imitating the physiologic pulsations of blood flow in an un branched artery, the viscosity (η') and elasticity (η") of whole blood and plasma were measured (diameter of the capillary: 0.9928 mm; pulse rate: 2/s; shear rate: γ=0.03-200/s; tem perature : 37°C). In arteriosclerotic patients a sta tistically significant elevation of the viscoelasticity of whole blood and plasma was found. In addition, plasma fibrinogen levels were aug mented in the patients' groups. Clot ting parameters (Quick, partial thromboplastin time, platelet count) and total serum protein levels were in the normal range in all patients inves tigated. In conclusion the question arises whether the increase of blood vis coelasticity is an additional risk fac tor for patients with arteriosclerotic disease or if it is just a consequence of the underlying disease. The authors' observations concerning blood vis coelasticity support the clinical im portance of improving blood rheology by appropriate therapeutic measures.