Effects Of Reduced Red-Cell Deformability On Coronary Hemodynamics And Cardiac-Function

To evaluate the effects of reduced red cell deformability on coronary hemodynamics and cardiac function, the coronary artery was perfused with blood containing partially hardened red cells pretreated with glutaraldehyde (gblood) in dogs. During 30 min of gblood perfusion, the coronary flow(CF) decreased and the coronary vascular resistance (CVR) increased (p<0.01); the regional and global left ventricular function were impaired significantly with p<0.01 for all the measured variables; and the myocardial ultrastructural changes were characterized by a severe trapping of red cells in capillary and other moderate ischemic injuries. Pretreatment with aspirin could markedly attenuate the extent of the above changes while alpha-adrenergic blockade with phentolamine did not alter these changes. In sharp contrast to the intracoronary infusion route, gblood infused through intravenous route showed no effects on CVR and cardiac function. All the changes initiated by intracoronary perfusion of gblood were similar in nature to those induced by ischemia. Thus, red cells with reduced deformability perfused into coronary artery, but not femoral vein, caused a significant decrease in CF and the resultant impairment of cardiac function. The reduction in CF was not due merely to plugging up the circulation by abnormal red cells, but may also be mediated through platelet aggregation or release of some vasoconstrictor substances from platelets.