Neural modulation of myocardial oxygen consumption: experiments and model study based on the alternative Starling curve description

The aim of this study is to analyze the relation between myocardial oxygen consumption (MVO₂) and end-systolic volume (ESV) in dependence of adrenergic stimulation or blockade in the normal left ventricle. The authors analyzed MVO₂ and volumetric data of 5 chronically instrumented dogs measured during rest and exercise, while protocol were performed with and without beta-blockade. Then the authors constructed their overall Alternative Starling Curve (ASC) by plotting ESV versus end-diastolic volume (EDV). Subsequently, the authors carried out an analysis, while employing an extended model compared with the Pressure-Volume-Area (PVA) for MVO₂ prediction as originally proposed by Suga (1990). This mathematical model is validated by comparison with pertinent data obtained by labeled C-acetate PET studies in healthy humans. The authors´ results indicate a close resemblance between theoretically predicted MVO₂ data and actual measurements performed in humans and dogs. In addition, this study suggests neural modulation of the MVO₂ESV relationship by illustrating the effects of various adrenergic interventions