Variation in Emax of the left ventricle among mammals

A mechanical relationship is provided that expresses the maximum elastance of the left ventricle in terms of its muscle volume or mass. The relation is derived assuming that the function of the cardiac sarcomere is invariant among different species of mammals. The nonlinear geometric functions are linearized for application to the linear time-varying elastance model of the heart. The results indicate that elastance, E_max, increases with decreasing muscle volume, V_mus, in an approximately logarithmic manner. The computed values of elastance are in good agreement with the data for various mammals. The analysis permits the prediction of E _max across species boundaries and permits its normalization due to variation in heart size, without assuming preload and afterload