A quantitative understanding of the changes in coronary, pulmonary and systemic hemodynamic variables and their effect on myocardial supply and demand is important to the better management of anesthetic care of patients with impaired cardiac function. Animal studies have identified those hemodynamic factors that play an important role in determining the balance between oxygen supply and demand for the myocardium. These include myocardial contractility, left ventricular end-diastolic volume, systemic arterial pressure, systemic vascular resistance, and heart rate. The interactions of these factors are complex and their combined effects on myocardial oxygen supply and demand are difficult to predict a priori.

The objective of this work was to construct a mathematical model of the cardiovascular system which will allow us to simulate the effects of changes in one or more of those hemodynamic parameters on myocardial supply and demand. The model used is a combination of several models which have been reported in the literature, along with our own modifications. The important feature of the model is that it is dynamic in nature and thus it is helpful in real time analysis. The model is also useful to conceptualize the problem and test relationships, helping researchers frame hypothesis and design experiments.