Biomaterial Database

Free-wall shortening and relaxation during ejection in the canine right ventricle. 1980

H Pouleur, and J Lefèvre, and H Van Mechelen, and A A Charlier

Relations between shortening, velocity of shortening, and relaxation of inflow and outflow segments of the right ventricular (RV) free wall (FW) were examined during ejection in 12 open-chest dogs after pharmacologic blockade by recording RV pressures, RVFW dimensions (piezoelectric crystals), and pulmonary blood flow. At heart rates of 113 +/0 8 (SD) beats/min, investigated segments remained isometric or even lengthened before the end of ejection. Tension-length data in the outflow tract converged at the time of peak systolic tension toward a common linear relation (average slope 65 +/- 10 cmH2O/mm, average intercept 5.9 +/- 0.9 mm), but markedly deviated from this line at the end of ejection. Consistent relations between peak tension and mean velocity of shortening were only observed during the first part of ejection. In addition the rate of segmental isometric relaxation, estimated from RV pressure fall was load dependent (e.g., +60% increase in relaxation rate when RVFW end-diastolic segment length increased from 12.9 +/- 0.8 to 13.5 +/- 0.8 mm). We conclude that under normal conditions, the tension-velocity-length relations of the RVFW are comparable to those of the left ventricle during the first part of ejection only. We also conclude that RV relaxation is load dependent and that a significant part of RV ejection occurs during RVFW relaxation.

UI	MeSH Term	Description	Entries
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
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
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
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
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002302	Cardiac Output	The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).	Cardiac Outputs,Output, Cardiac,Outputs, Cardiac
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
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
D016276	Ventricular Function	The hemodynamic and electrophysiological action of the HEART VENTRICLES.	Function, Ventricular,Functions, Ventricular,Ventricular Functions