Fluorocarbon and dextran hemodilution in myocardial ischemia

The effect of hemodilution, with a fluorocarbon erythrocyte substitute and with dextran, on myocardial ischemia induced by occlusion of the left anterior descending coronary artery was investigated in anesthetized dogs. The resulting changes were compared to those in a control group subjected to a sham-exchange procedure. The hematocrit was reduced to 23% to 26% by dilution with fluorocarbon and dextran, while it was maintained at 42% to 46% in the control group. At similar hematocrit levels, during ventilation with 100% oxygen, the fluorocarbon-diluted blood transported 4 ml/dl more oxygen in the plasma phase than the dextran-diluted blood. Left ventricular function was not significantly altered and there was a marked improvement of blood flow to the ischemic zone. The mass of dehydrogenase-stained ischemic myocardium (21% of left ventricular mass) was marginally (p less than 0.06) smaller in the dogs with fluorocarbon-diluted blood than in the control group (29% of left ventricular mass). The output of creatine phosphokinase by the heart was also reduced (p less than 0.05) by hemodilution with fluorocarbon. These findings suggest that hemodilution with an oxygen-transporting blood substitute may have marginal beneficial effects on the collateral perfusion of acutely ischemic myocardium following sudden coronary artery occlusion.