Inadequate subendocardial oxygen delivery during perfluorocarbon perfusion in a canine model of ischemia

Abstract

Perfusion of the coronary artery distal to an occlusion was performed in 16 canine preparations to compare the mechanical perfusion of autologous blood to the perfluorocarbon fluosol DA, 20% emulsion (FDA-20). Both substances were perfused under similar conditions (30, 60, and 80 ml/min) and regional electrograms, contractility, and coronary perfusion were measured relative to native coronary perfusion. Autologous blood (60 and 80 ml/min) produced a significant increase in regional (epicardial, midmyocardial, and endocardial) and transmural flow, but not in the endocardial/epicardial perfusion ratio. No other significant changes were observed during autologous blood perfusion. In contrast, FDA-20 perfusion resulted in significant ST depression (−1.8 ± 0.2, −1.7 ± 0.2, and −1.3 ± 0.3 mm) at 30, 60, and 80 ml/min, respectively. FDA-20 also induced a significant decrease in distal diastolic coronary pressure and resistance, a significant decrease in the endocardial/epicardial perfusion ratio at all three perfusion rates, and a significant reduction in delivery of O 2 to the subendocardium. These results indicate that autologous blood perfusion of the distal coronary artery during occlusion preserves myocardial function to a better degree than does FDA-20.