Effect of intramyocardial pressure on the phasic flow in the intraventricular septal artery.

Phasic flow in the intraventricular septal artery (SA) was measured by an electromagnetic flowmeter in anaesthetized dogs. The ratio of systolic to diastolic flow was less in the intramyocardial artery than in an epicardial (circumflex) artery. The SA systolic to diastolic ratio was further depressed when elevations in intramyocardial pressure were produced. These studies lend insight into the relationships between intramyocardial pressure and coronary arterial flow.