Biomaterial Database

The linear relation between oxygen consumption and pressure-volume area can be reconciled with the Fenn effect in dog left ventricle. 1989

T Nozawa, and Y Yasumura, and S Futaki, and N Tanaka, and H Suga

Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Osaka, Japan.

We studied the Fenn effect in 12 excised cross-circulated dog left ventricles in control contractility and in a contractility enhanced by dobutamine or depressed by propranolol. The additional oxygen consumption (Vo2) in an ejecting contraction compared with that found in an isovolumic contraction at a comparable end-systolic pressure was considered to constitute the cardiac Fenn effect. We examined whether this load-dependent Vo2 could be reconciled with the linear relation between Vo2 and pressure-volume area (PVA) common for both ejecting and isovolumic contractions that has so far been consistently observed and was presently confirmed. PVA is a specific area in the pressure-volume diagram, represents the total mechanical energy generated by each contraction, and consists of external mechanical work (EW) and mechanical potential energy. Because potential energy is common in the isovolumic and ejecting contractions producing the same end-systolic pressure, PVA of the ejecting contraction is greater by EW than that of the isovolumic contraction. Despite this difference in PVA by EW, the Vo2-PVA relation was always linear and load independent regardless of the isovolumic and ejecting contractions in a given heart in any given contractile state. By contrast, the upward convex Vo2-end-systolic pressure relation was higher for ejecting contractions than the downward convex Vo2-end-systolic pressure relation for isovolumic contractions in each contractile state. The difference of Vo2 between the ejecting and isovolumic contractions was proportional to EW at comparable end-systolic pressure. The slope of the additional Vo2 of ejecting contractions plotted against their EW had a slope close to the slope of the Vo2-PVA relation. Thus, the load-independent linear Vo2-PVA relation can be reconciled with the cardiac Fenn effect.

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
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
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
D001810	Blood Volume	Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.	Blood Volumes,Volume, Blood,Volumes, Blood
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
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
D006352	Heart Ventricles	The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.	Cardiac Ventricle,Cardiac Ventricles,Heart Ventricle,Left Ventricle,Right Ventricle,Left Ventricles,Right Ventricles,Ventricle, Cardiac,Ventricle, Heart,Ventricle, Left,Ventricle, Right,Ventricles, Cardiac,Ventricles, Heart,Ventricles, Left,Ventricles, Right
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
D013599	Systole	Period of contraction of the HEART, especially of the HEART VENTRICLES.	Systolic Time Interval,Interval, Systolic Time,Intervals, Systolic Time,Systoles,Systolic Time Intervals,Time Interval, Systolic,Time Intervals, Systolic