Computerized left ventricular mechanics and control system analyses models relevant for cardiac diagnosis

Two left ventricular models, relevant to cardiac diagnosis, are presented. The first is a Computer-based Finite Element Stress Analysis model of the left ventricle (LV) aimed to account for the irregular left ventricular geometry obtainable from single plane cineangiocardiography. The in vivo data for the model consists of instantaneous left ventricular chamber pressure and cine. The calculated wall stresses are compared with idealized geometry models. The finite element model is better able to delineate the stress concentrations at sites of large curvatures. The second model consists of a control system model of the LV, which formulates the interaction of the mechanics of the LV and the lumped parameter circulatory system by the central nervous system's monitoring of the mean arterial pressure, regulation of the heart rate, left ventricular contractility and the perepheral impedance. The model is parametrically simulated for a subject by means of the continuous system modelling program (CSMP); then the simulated model's response to a physiological stress simulating pressure perturbation is determined; the model enables an assessment of the physiological stress sustaining capacity of a subject. © 1973.