Mechanical determinants of myocardial oxygen consumption in conscious dogs. Am J Physiol 1995 Aug;269(2 Pt 2):H609-20
Date
08/11/1995Pubmed ID
7653625DOI
10.1152/ajpheart.1995.269.2.H609Scopus ID
2-s2.0-0029129598 (requires institutional sign-in at Scopus site) 21 CitationsAbstract
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.
Author List
Elbeery JR, Lucke JC, Feneley MP, Maier GW, Owen CH, Lilly RE, Savitt MA, Hickey MS, Gall SA Jr, Davis JWMESH terms used to index this publication - Major topics in bold
AnimalsBiomechanical Phenomena
Constriction, Pathologic
Dogs
Energy Metabolism
Heart Rate
Hemodynamics
Homeostasis
In Vitro Techniques
Models, Cardiovascular
Myocardial Contraction
Myocardium
Oxygen Consumption
Venae Cavae
