Induced change in heart metabolism as a primary determinant of heart performance

Publisher Website
Google Scholar
Abstract
In 65 isolated dog hearts, left ventricular isometric developed tension (LVDT) or isotonic shortening (LVS) were measured at various levels of coronary blood flow (CBF) and heart load. It was found that imposed changes in CBF (over a wide range) 1) caused directionally similar changes in LVDT (or LVS) and O2 consumption at any given heart load (metabolic effect); 2) governed the magnitude of change in LVDT or LVS in response to an altered load (Starling effect). In some hearts autoregulation of CBF occurred which obscured but did not obliterate the effect. Autoregulation of CBF could be diminished or abolished by lowering arterial O2 saturation and restored by resaturation. It is suggested that CBF rate may be an important normal determinant of cardiac work capacity and performance by regulating the delivery rate of O2 and substrate as well as removal rate of CO2 and other metabolites in various parts of the myocardium. Possible defects in experiments reported by others failing to show a dependence of work performance on CBF rate are mentioned.

This publication has 1 reference indexed in Scilit: