Effects of coronary occlusion on myocardial oxygen and pulsatile intramyocardial pressure

Local oxygen partial pressure in terms of O2-availability and pulsatile intramyocardial pressure of the left ventricular myocardium of anaesthetized open-chest dogs have been measured simultaneously by means of a piezoelectric ceramic and a platinum electrode. The tissue PO2 decreases more slowly than the pulsatile intramyocardial pressure during a transient acute occlusion of the anterior descending branch of the coronary artery. The slow decrease in the tissue PO2 seems to be explicable by the assumption that the local myocardial contractile force decreases quickly due to an unknown factor during the acute coronary occlusion and that the O2-consumption of the local myocardial tissue is reduced in accordance with the rapid decrease in the contractile force.