A COMPUTER MODEL OF MYOCARDIAL SQUEEZING AND INTRAMYOCARDIAL FLOW DURING GRADED CORONARY ARTERY STENOSIS IN THE PRESENCE OF CORONARY SINUS INTERVENTIONS

A mathematical model of the left coronary circulation is used to calculate phasic arterial and intramyocardial flows under normal conditions, gradual stenosis, and full occlusion of the left anterior descending coronary artery. Experimental data reported in literature are compiled to derive a mathematical formula for the physiologic link between two model parameters: the resistance across the stenosis and the extravasal squeezing pressure within the LAD-dependent region of the myocardium. Matching pairs of resistance and decrease in squeezing form “infarction traces.” Model simulations yield the changes in coronary and intramyocardial flows along these infarction traces. The model was applied to alternating brief coronary sinus occlusions and coronary sinus release. The retrograde blood flow from the coronary veins to the capillaries during coronary sinus occlusion was estimated to range between 47% and 88% of the forward blood flow under patent coronary sinus conditions.