Protection against myocardial ischaemia by prior haemodilution with fluorocarbon emulsions.

The possible prophylactic effects of Fluosol-DA 20% (FDA) haemodilution against myocardial hypoxia were studied in two groups of anaesthetized immature pigs. Precalibrated 200-micron diameter oxygen microelectrodes were inserted to the myocardium of the left ventricle. One group of animals was haemodiluted with FDA and both groups received 100% oxygen (plus halothane). The lower one-third of the left anterior descending coronary artery was occluded; this caused no significant cardiovascular changes. Analysis from the microelectrodes in the most hypoxic areas of the myocardium revealed significant decreases in myocardial oxygen tension (PmO2) in the control group 15 min after occlusion in the FDA-diluted group. Analysis of other electrodes suggested greater hyperaemic compensatory response in ischaemic border areas in the FDA-treated group.