How does intramyocardial pressure impact intramyocardial flow during coronary sinus occlusion in a computer model?
This computer model study suggests that retrograde flow during coronary sinus occlusion is biphasically dependent on intramyocardial pressure, peaking at moderate pressures and declining at very high pressures.
A model consisting of an arterial, a capillary, and a venous compartment was developed to reproduce experimentally determined hemodynamic results of the arterial and venous sides of the coronary circulation. From the model, intramyocardial flow between capillaries and veins, which is inaccessable to measurement, was then estimated. Results are given for normal perfusion and coronary sinus occlusion conditions. For both conditions, intramyocardial pressure was varied within the model in order to study its impact on intramyocardial flow. For low and moderate intramyocardial pressures under coronary sinus occlusion, retrograde flow from veins to capillaries was seen to increase with increasing intramyocardial pressure. However, for very high values of intramyocardial pressure, which are close to left ventricular pressure, retrograde flow declined.
Schreiner et al. (Mon,) studied this question.