[A biomechanical model of left ventricle regional ischemia: a computer simulation]

Objective. To analyze the biomechanical mechanism of left ventricular regional ischemia and to investigate the changes of myocardial contractilities in different ventricular regions during regional ischemia. Method. A time-dependent mathematical model for simulating left ventricle regional ischemia has been developed basing on geometry of left ventricle, spatial angle distribution, propagation of electrical activation signals and biomechanical properties of cardiac muscle fibers. Then the model was incorporated into a multi-element circulatory model established by us previously. By using this model, some simulation experiments relating myocardium contractility to regional ischemia in inner or outer layers of ventricular wall were performed. Result. Myocardial contractility of the ischemic layers decreased whereas that of normal layers increased significantly. Compared with ischemia in outer layers of ventricular wall, ischemia in inner layers of ventricular wall had more effects upon cardiac function. Conclusion. The myocardium of normal region had the ability to increase its contractility in order to maintain a normal cardiac function. A method to simulate the relationship between cardiovascular function and left ventricular regional ischemia was developed.