Biomaterial Database

Acute aortic stenosis in the conscious dog: effects of inotropic state on heart rate. 1986

I H Zucker, and M J Niebauer, and K G Cornish

Effects of acute distension of the left ventricle on heart rate were studied in conscious, instrumented dogs. In intact dogs, increasing left ventricular (LV) systolic pressure by a maximum of 77.6 +/- 3.6 mmHg from a control of 123.1 +/- 3.6 and LV end-diastolic pressure by a maximum of 24.1 +/- 2.0 mmHg from a control of 8.5 +/- 1.3 did not result in any consistent change in heart rate. Reduction of arterial pressure with sodium nitroprusside caused an increase in heart rate to 143.9 +/- 13.8 beats/min. With baroreceptors unloaded, increasing LV pressure by a similar degree as in the control group now resulted in consistent and significant bradycardia. Removal of arterial baroreceptors in a final group of dogs abolished the baroreflex. Increasing LV pressure by aortic stenosis now resulted in a stimulus-dependent decrease in heart rate that was significantly greater than that in the nitroprusside group. Both administration of atropine and bilateral cervical vagotomy abolished bradycardia. The second part of this study was concerned with effects of increases in LV inotropic state on heart rate change evoked by aortic stenosis. Each group was infused with intracoronary epinephrine. Infusion of epinephrine (12.5-50.0 ng . kg-1 . min-1) significantly increased LV dP/dt without any significant change in heart rate or mean arterial blood pressure. Aortic stenosis during epinephrine infusion did not result in any significant difference in heart rate responses in any group studied. It is concluded that LV distension can cause a reduction in heart rate that is opposed by the presence of arterial baroreceptors and that increases in LV myocardial contractility do not have any effect on the magnitude of this response.

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
D009599	Nitroprusside	A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.	Nitroferricyanide,Sodium Nitroprusside,Cyanonitrosylferrate,Ketostix,Naniprus,Nipride,Nipruton,Nitriate,Nitropress,Nitroprussiat Fides,Nitroprusside, Disodium Salt,Nitroprusside, Disodium Salt, Dihydrate,Disodium Salt Nitroprusside,Nitroprusside, Sodium
D011311	Pressoreceptors	Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.	Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
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
D004837	Epinephrine	The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.	Adrenaline,4-(1-Hydroxy-2-(methylamino)ethyl)-1,2-benzenediol,Adrenaline Acid Tartrate,Adrenaline Bitartrate,Adrenaline Hydrochloride,Epifrin,Epinephrine Acetate,Epinephrine Bitartrate,Epinephrine Hydrochloride,Epinephrine Hydrogen Tartrate,Epitrate,Lyophrin,Medihaler-Epi,Acetate, Epinephrine
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
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
D001024	Aortic Valve Stenosis	A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.	Aortic Stenosis,Aortic Valve Stenoses,Stenoses, Aortic,Stenoses, Aortic Valve,Stenosis, Aortic,Stenosis, Aortic Valve,Valve Stenoses, Aortic,Valve Stenosis, Aortic
D001285	Atropine	An alkaloid, originally from Atropa belladonna, but found in other plants, mainly SOLANACEAE. Hyoscyamine is the 3(S)-endo isomer of atropine.	AtroPen,Atropin Augenöl,Atropine Sulfate,Atropine Sulfate Anhydrous,Atropinol,Anhydrous, Atropine Sulfate,Augenöl, Atropin,Sulfate Anhydrous, Atropine,Sulfate, Atropine