Studying the mechanics of left ventricular contraction

Several interesting aspects of the end-systolic pressure-volume relation (ESPVR) are discussed in this study, including: a) A possibility to introduce, in an explicit manner, the active force of the myocardium in the formalism describing the PVR of the left ventricle. b) A possibility to express the ventriculo-arterial coupling by using the ratio E/sub max//e/sub am/, in a way to distinguish between the normal physiological state and the mildly or severely depressed state of the heart. The possibility of also expressing this coupling by using directly different areas under ESPVR has been indicated. A third method, not discussed here, is to use the windkessel model. c) The relationship between oxygen consumption and all the areas under ESPVR. d) A possible mechanism of adaptation to short- or long-term variation in load condition by changing ESPVR in a way to create an systemic work reserve (SWR). e) A possibility to use different areas under ESPVR for clinical diagnostic purposes; an example for SWR and SWR/SW is given. f) A possibility of noninvasive clinical application of various results of this study.