Subepicardial steal and reduction of myocardial oxygen consumption by adenosine.

The direct effects of adenosine on cardiac oxygen balance, hemodynamics and regional myocardial perfusion were studied in isolated canine hearts. Intracoronary infusion of adenosine produced a dose-dependent shift in the transmural distribution of coronary blood flow away from left ventricular subendocardium and a reduction in myocardial oxygen consumption (MVO2). The data suggest that adenosine may partially decrease MVO2 by a redistribution of flow from a high to low oxygen-extracting region of the myocardium.