Left ventricular stresses in the intact human heart.

A set of stress differential equations of equilibrium is presented for a thick prolate spheroid which is the assumed shape for the left ventricle. An analysis for the stresses in the ventricular wall indicates that maximum stresses occur at the inner layers and decrease to a minimum at the epicardial surface, a result that is partially validated by experiment. Simple expressions are available for the evaluation of maximum stresses which occur at the equator and are suitable for small laboratory-oriented digital computers employed in the clinical evaluation of patient status. The surprising result is that Laplace's law yields practical values for mean stresses in thick-walled ventricles.