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Titolo:
PRESSURE WAVE-PROPAGATION AND INPUT IMPEDANCE IN THORACIC AORTA OF CONSCIOUS NEWBORN SHEEP
Autore:
ADAMSON SL; WHITELEY KJ; LANGILLE BL;
Indirizzi:
MT SINAI HOSP,SAMUEL LUNENFELD RES INST,RM 138-P,600 UNIV AVE TORONTOON M5G 1X5 CANADA TORONTO HOSP,RES INST TORONTO ON M5G 1X5 CANADA
Titolo Testata:
American journal of physiology. Heart and circulatory physiology
fascicolo: 2, volume: 37, anno: 1995,
pagine: 558 - 568
SICI:
0363-6135(1995)37:2<558:PWAIII>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
BLOOD-FLOW DISTRIBUTION; BIRTH-RELATED EVENTS; FETAL SHEEP; PERINATAL-PERIOD; LAMBS; CIRCULATION; REFLECTION; RESPONSES; DIAMETER;
Keywords:
LAMB; WAVE VELOCITY; HEMODYNAMICS; WAVE REFLECTIONS; NOREPINEPHRINE; FEEDING; ANGIOTENSIN II; NITROPRUSSIDE; BIRTH; IMPEDANCE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
30
Recensione:
Indirizzi per estratti:
Citazione:
S.L. Adamson et al., "PRESSURE WAVE-PROPAGATION AND INPUT IMPEDANCE IN THORACIC AORTA OF CONSCIOUS NEWBORN SHEEP", American journal of physiology. Heart and circulatory physiology, 37(2), 1995, pp. 558-568

Abstract

Aortic hemodynamics were examined in eight conscious newborn sheep. Flow and pressure in the thoracic aorta and pressure in the distal abdominal aorta were measured under control conditions and during pressurechanges caused by bottle feeding or during intravenous infusions of nitroprusside, norepinephrine, or angiotensin II. Vasoconstriction affected aortic impedance, pressure wave amplification, and wave velocity similarly whether induced by feeding or by drugs. Central hemodynamicsin the lamb were surprisingly similar to hemodynamics in the sheep fetus despite major changes in cardiovascular function at birth, largelybecause pressure-related increases in pulse wave velocity postpartum compensated for increased arterial lengths and increased heart rate. Wave reflection effects on pressure-flow relations were more prominent during vasoconstriction and less prominent during nitroprusside. Wave reflections in both lambs and fetal sheep return to the heart in earlydiastole; therefore, they do not add to ventricular afterload. Early diastolic return of reflected waves characterizes adults of many species, and demonstration of the phenomenon throughout the perinatal period reinforces arguments for its adaptive value.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 04:55:36