Effect of Hypertrophy and Dilatation on the Left Ventricular Pressure-Volume Relation

Analysis Based on the Large Deformation Theory

Abstract

The pressure-volume relations of the left ventricle were derived at different geometries by using a homogeneous and isotropic spherical shell model based on the large deformation theory. In this study, the mechanical behavior of the unit myocardium was assumed to be equal to all the hearts.
The results obtained were as follows : 1. At the same undeformed left ventricular volume, changes in the left ventricular weight exerted only a slight influence on the ventricular pressure-volume relation. 2. However, an increase in the undeformed left ventricular volume caused a marked change in the left ventricular pressure-volume relation. Thus the rise in the left ventricular compliance was obvious. But the relation between the ratio of the actual volume change of the left ventricle to undeformed volume and left ventricular pressure showed no apparent differences. 3. Moreover, the relation between the ratio of the left ventricular volume to weight and left ventricular pressure could be determined by the undeformed left ventricular geometry, namely the ratio of the left ventricular undeformed volume to weight.