Left ventricular mechanoenergetics in small animals. 2004

M Takaki
Department of Physiology II, Nara Medical University, Kashihara, Nara, 634-8521 Japan. mtakaki@naramed-u.ac.jp

Studies on left ventricular mechanical work and energetics in rat and mouse hearts are reviewed. First, left ventricular linear end-systolic pressure-volume relation (ESPVR) and curved end-diastolic pressure-volume relation (EDPVR) in canine hearts and left ventricular curved ESPVR and curved EDPVR in rat hearts are reviewed. Second, as an index for total mechanical energy per beat in rat hearts as in canine hearts, a systolic pressure-volume area (PVA) is proposed. By the use of our original system for measuring continuous oxygen consumption for rat left ventricular mechanical work, the linear left ventricular myocardial oxygen consumption per beat (VO2)-PVA relation is obtained as in canine hearts. The slope of VO2-PVA relation (oxygen cost of PVA) indicates a ratio of chemomechanical energy transduction. VO2 intercept (PVA-independent VO2) indicates the summation of oxygen consumption for Ca2+ handling in excitation-contraction coupling and for basal metabolism. An equivalent maximal elastance (eEmax) is proposed as a new left ventricular contractility index based on PVA at the midrange left ventricular volume. The slope of the linear relation between PVA-independent VO2 and eEmax (oxygen cost of eEmax) indicates changes in oxygen consumption for Ca2+ handling in excitation-contraction coupling per unit changes in left ventricular contractility. The key framework of VO2-PVA-eEmax can give us a better understanding for the biology and mechanisms of physiological and various failing rat heart models in terms of mechanical work and energetics.

UI MeSH Term Description Entries
D009200 Myocardial Contraction Contractile activity of the MYOCARDIUM. Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D010101 Oxygen Consumption The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346) Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D004734 Energy Metabolism The chemical reactions involved in the production and utilization of various forms of energy in cells. Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D013318 Stroke Volume The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume. Ventricular Ejection Fraction,Ventricular End-Diastolic Volume,Ventricular End-Systolic Volume,Ejection Fraction, Ventricular,Ejection Fractions, Ventricular,End-Diastolic Volume, Ventricular,End-Diastolic Volumes, Ventricular,End-Systolic Volume, Ventricular,End-Systolic Volumes, Ventricular,Fraction, Ventricular Ejection,Fractions, Ventricular Ejection,Stroke Volumes,Ventricular Ejection Fractions,Ventricular End Diastolic Volume,Ventricular End Systolic Volume,Ventricular End-Diastolic Volumes,Ventricular End-Systolic Volumes,Volume, Stroke,Volume, Ventricular End-Diastolic,Volume, Ventricular End-Systolic,Volumes, Stroke,Volumes, Ventricular End-Diastolic,Volumes, Ventricular End-Systolic
D016276 Ventricular Function The hemodynamic and electrophysiological action of the HEART VENTRICLES. Function, Ventricular,Functions, Ventricular,Ventricular Functions
D016277 Ventricular Function, Left The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance. Left Ventricular Function,Function, Left Ventricular,Functions, Left Ventricular,Left Ventricular Functions,Ventricular Functions, Left
D051381 Rats The common name for the genus Rattus. Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus

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