Finite element analysis of embedded blood vessel mechanics

Cardiac pump function is closely linked to myocardial oxygen supply during the cardiac cycle. Variations in cardiac output must be met with concurrent shifts in tissue blood flow if changing myocardial oxygen requirements are to be satisfied. Of particular importance is the adequate perfusion of the left ventricular myocardium. Experimental evidence indicates that some ninety percent of left ventricular oxygen demand is generated during systolic contraction of the myocardium. Paradoxically, blood flow measurements in the left coronary artery suggest minimal systolic perfusion. The asynchronous, phasic character of left coronary blood flow and myocardial oxygen demand has prompted much research into the time dependent origins of coronary flow impedance. Various (sometimees conflicting) theories have been proposed, all of which suggest tissue blood delivery is significantly influenced by mechanical interactions between the myocardium and its embedded vascular network. Such interactions become particularly acute during systole, where myocardial contraction produces deformations and stress contractions which influence embedded vessel patency, coronary flow impedance, and effective driving pressure