[Oxygen tension in cardiac tissue and its consumption by the myocardium]

In the rat isolated and perfused heart, the rate of the oxygen consumption by the myocardium at an increased rate of perfusion increased much faster than the volume of the tissue hyperoxic areas. No correlation of average tissue pO2 in separate experiments and the oxygen consumption, was found. The increased oxygen consumption by arrested heart at increased perfusion rate seems to be due to physical conditions of the perfusion rather than to excessive oxygenation of the tissue.