Left ventricular function: time-varying elastance and left ventricular aortic coupling

TitleLeft ventricular function: time-varying elastance and left ventricular aortic coupling
Publication TypeJournal Article
Year of Publication2016
AuthorsWalley, KR
JournalCritical Care
Volume20
Start Page270
Date Published09/2016
ISSNPrint: 1364-8535; Online: 1466-609X
Abstract

Many aspects of left ventricular function are explained by considering ventricular pressure-volume characteristics. Contractility is best measured by the slope, Emax, of the end-systolic pressure-volume relationship. Ventricular systole is usefully characterized by a time-varying elastance (ΔP/ΔV). An extended area, the pressure-volume area, subtended by the ventricular pressure-volume loop (useful mechanical work) and the ESPVR (energy expended without mechanical work), is linearly related to myocardial oxygen consumption per beat. For energetically efficient systolic ejection ventricular elastance should be, and is, matched to aortic elastance. Without matching, the fraction of energy expended without mechanical work increases and energy is lost during ejection across the aortic valve. Ventricular function curves, derived from ventricular pressure-volume characteristics, interact with venous return curves to regulate cardiac output. Thus, consideration of ventricular pressure-volume relationships highlight features that allow the heart to efficiently respond to any demand for cardiac output and oxygen delivery.

DOI10.1186/s13054-016-1439-6