Abstract
In this study, we have tried to understand why the left ventricle (LV) is not a homogeneous sphere. An experimental model of a spherical ventricle was developed. The chamber was configured as a mathematical model, and the wall properties were represented by isolated cardiac muscles. The stroke work of the spherical LV when modelling different types of inhomogeneity in the wall structure was investigated. It was found that the emergence of even slight inhomogeneity in a spherical ventricle inevitably results in a diminution of pump function. It was concluded that at a given level of the myocardial contractility, a homogeneous spherical LV would not have any functional reserve, ie no ability to maintain pump function in case of additional load. Functional reserve can be achieved only with a certain degree of inhomogeneity. Thus, inhomogeneity in the normal left ventricular wall structure constitutes a strategic functional reserve that is absent in a homogeneous spherical ventricle.