Mechanical determinants of myocardial oxygen consumption in conscious dogs.

Published

Journal Article

A new practical descriptor of metabolic to mechanical myocardial energy transfer (MET), termed the virtual work model, was evaluated in 32 conscious dogs and in 8 isolated canine hearts. An index of total mechanical energy expenditure (TME) was calculated as the sum of external energy (stroke work) and an internal energy index of heat (left ventricular end-diastolic volume times left ventricular mean ejection pressure). Physiological comparison of TME (x-axis) and myocardial oxygen consumption (MVO2; y-axis) yielded highly linear MET relationships (mean r = 0.93 +/- 0.07), with an average slope of 0.86 +/- 0.39 (SD) and a y-intercept of 9.1 +/- 6.4 mW/ml myocardium. The linear MVO2-TME relationship did not vary under steady-state vs. dynamic vena caval occlusion, increased heart rate, increased afterload, or increased inotropic state with calcium infusion. Compared with five other indexes of myocardial energetics, the virtual work model of MET was the most linear, the most practical in not requiring determination of the end-systolic pressure-volume relationship, and the most accurate predictor of MVO2 under normal and altered hemodynamic conditions.

Full Text

Duke Authors

Cited Authors

  • Elbeery, JR; Lucke, JC; Feneley, MP; Maier, GW; Owen, CH; Lilly, RE; Savitt, MA; Hickey, MS; Gall, SA; Davis, JW

Published Date

  • August 1995

Published In

Volume / Issue

  • 269 / 2 Pt 2

Start / End Page

  • H609 - H620

PubMed ID

  • 7653625

Pubmed Central ID

  • 7653625

Electronic International Standard Serial Number (EISSN)

  • 2163-5773

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpheart.1995.269.2.h609

Language

  • eng