Mechanical determinants of myocardial oxygen consumption in conscious dogs.
Journal Article (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
International Standard Serial Number (ISSN)
- 0002-9513
Digital Object Identifier (DOI)
- 10.1152/ajpheart.1995.269.2.H609
Language
- eng
Conference Location
- United States