Blood viscosity,red cell rigidity,and arterial blood pressure in patients with severe coronary occlusions or chest pains. Effect of submaximal exercise test.

Abstract

Twelve patients suffering from severe coronary artery occlusions and 24 patients with chest pains (but no evidence of coronary occlusion) have been investigated for blood viscosity, plasma viscosity and rigidity (Tk) of red cells, both prior to and after the submaximal (bike ergometer) exercise tests. Blood viscosity (measured at shear rate of 180 rec. sec.) was found to correlate significantly with the diastolic blood pressure in patients with severe coronary occlusions, both at rest and during/after the exercise test. Blood viscosity correlated significantly with the diastolic blood pressure in patients with chest pains only after the exercise test. Haematocrit did not correlate with the diastolic blood pressure. However, all patients, and all men, showed significant and positive correlations between diastolic blood pressure (at rest or at maximum) and the rigidity (Tk) of red cells (the latter calculated from the blood viscosity equation). Blood viscosity and rigidity of red cells were increased in patients at P < 0.001 when compared with normal values.