Blood hyperviscosity and peripheral ischemia;The secondary hyperviscosity syndrome of ischemizing vascular diseases

The aim of this paper is the study of the secondary hyperviscosity syndrome of ischemizing vascular diseases which becomes important during exercise. An experimental model was set up for the study of arterial and venous hemorheological parameters during an isotonic exercise in a lower limb of patients suffering from peripheral obliterative arterial disease with intermittent claudication. The exercise was performed on a pedal ergometer with a dynamic brake of our design, until the onset of claudication. Before and after exercise, arterial, femoral venous, and brachial venous blood was withdrawn. The whole blood viscosity at various shear rates, and whole blood and washed red cell filterability were controlled. These hemorheological parameters were correlated to the variations of other parameters indicative of oxigen transfer and local acid-base equilibrium, of lactid acid production, of leucocyte and platelet activation and of fibrinolysis, always in arterial, femoral venous, and brachial venous blood. The results confirm that there is a worsening of the local blood fluidity in patients after exercise which is simultaneous and proportional to lactic acidosis and to venous pO₂ fall. The reduction of whole blood filterability is more evident than that of washed red cells. The activation of platelets (beta-thromboglobulin increase) and of fibrinolysis (euglobulin-lysis-time shortening) in femoral venous blood was also pointed out. The insignificant variation of lactoferrin and of the number of leucocytes suggests a scarce involvement of granulocytes in this experimental model.