Modeling of hypertension-induced left ventricular hypertrophy

A theoretical model of the left ventricle capable of predicting shape and size in relation to the loading and metabolic conditions is presented and applied to the study of hypertension-induced hypertrophy (HIH). Oxygen consumption per gram tissue is imposed as the control parameter. HIH is produced by progressively increasing mean aortic pressure (MAP) on the normo-tensive model. The focus is on the hemodynamic variations that accompany HIH. The model results clearly indicate an increase in wall-thickness-to-diameter ratio of the left ventricle as the MAP is increased, while the cardiac output is constant (concentric hypertrophy). The hemodynamic parameters show an increase in stroke volume, stroke work, and global oxygen consumption; a decrease in heart rate and efficiency; and relatively constant mean fiber stress. Hence, regulation of metabolic rates in the myocyte appears to be a basic mechanism that leads to HIH