Left Ventricular Model Taking Account of Residual Stress

Abstract

At the present time, there is no adequate method for experimental measurement of wall stresses in the intact ventricle. Thus, many mechanical models to predict such stresses have been proposed, in which the residual stress was ignored so that the circumferential stress at the endocardium of the left ventricle was extremely large compared with that at the epicardium. The work expressed, such as oxygen consumption, is supposed to be almost uniform through the wall thickness, or to be somewhat larger at the endocardium than at the epicardium. The models may be improved by taking account of residual stress. To take residual stress into account in mechanical models, one must measure residual strains in the no-load state of the left ventricle. The residual strains were calculated by using sliced canine left ventricles obtained during isovolumic contraction. The residual strains determined from the experiment were applied to the model proposed in the present paper and the distributions of the wall stresses were obtained. As a result, the stress concentration at the endocardium of the left ventricle was found to be largely reduced. © 1994, The Japan Society of Mechanical Engineers. All rights reserved.