Stresses in Left Ventricular Wall and Biaxial Stress-Strain Relation of the Cardiac Muscle Fiber for the Potassium-Arrested Heart

Abstract

Wall stresses and pseudo-strain energy function (W) were determined analytically from the pressure-volume relationships taken from (6 hypertrophied and 5 normal) canine hearts on the basis of large elastic deformation theory by assuming a spherical geometry of the left ventricles. The biaxial stress-strain relation of the myocardium was obtained from the function W. This relation was found to be more appropriate than the uniaxial relations for comparison of ventricles having different pressure-volume relationships and/or different sizes, since the uniaxial relation cannot be determined uniquely only from the pressure-volume relationship.