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Titolo:
ARTERIAL WAVE-PROPAGATION PHENOMENA, VENTRICULAR WORK, AND POWER DISSIPATION
Autore:
BERGER DS; LI JKJ; NOORDERGRAAF A;
Indirizzi:
UNIV CHICAGO,DEPT MED,CARDIOL SECT,5841 S MARYLAND AVE CHICAGO IL 60637 RUTGERS STATE UNIV,DEPT BIOMED ENGN,CARDIOVASC RES LAB PISCATAWAY NJ 00000 UNIV PENN,DEPT BIOENGN,CARDIOVASC STUDIES UNIT PHILADELPHIA PA 19104
Titolo Testata:
Annals of biomedical engineering
fascicolo: 6, volume: 23, anno: 1995,
pagine: 804 - 811
SICI:
0090-6964(1995)23:6<804:AWPVWA>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
INPUT IMPEDANCE; HYPERTENSION; SYSTEM; REFLECTION;
Keywords:
WAVE REFLECTIONS; PULSE WAVE VELOCITY; STROKE WORK; ARTERIAL SYSTEM POWER DISSIPATION MODEL EXPERIMENTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
20
Recensione:
Indirizzi per estratti:
Citazione:
D.S. Berger et al., "ARTERIAL WAVE-PROPAGATION PHENOMENA, VENTRICULAR WORK, AND POWER DISSIPATION", Annals of biomedical engineering, 23(6), 1995, pp. 804-811

Abstract

The effects of wave propagation phenomena, namely global reflection coefficient (Gamma(G)[omega]) and pulse wave velocity (c(ph)), are studied in a model of the coupled left ventricle/arterial system. The leftventricle consists of a time-varying elastance, while the arterial system is modeled as a single, uniform, elastic tube terminating in a complex load. Manipulation of model parameters allowed for the precise control of Gamma(G)(omega) and c(ph) independent of each other, peripheral resistance, and characteristic impedance. Reduction of Gamma(g)(omega) and c(ph) were achieved through increases in load compliance and tube compliance, respectively. The equations describing the system were solved for left ventricular and aortic pressures and aortic flow. From these, stroke volume (SV), left ventricular stroke work (SW), and steady (W-s), oscillatory (W-o), and total power dissipation (W-t) in the arterial system were calculated. An index of arterial system efficiency was the ratio W-o/W-t (%W-o), with lower values indicating higherefficiency. Reduction of Gamma(G)(omega) yielded initial increases inW-s, while W-o increased for the entire range of Gamma(G)(omega), resulting in increased %W-o. This reduced efficiency is imposed on the ventricle, resulting in increased SW without increased SV. On the other hand, decreased c(ph) yielded in a steady increase in W-s and a biphasic response in W-o, resulting in reduced %W-o for most of the range ofreduced c(ph). These results suggest that differential effects on arterial system efficiency can result from reductions of Gamma(G)(omega) and c(ph). In terms of compliance, changes in arterial compliance can have different effects on efficiency, depending on where the compliance change takes place. Reasons for these results are suggested, and therole of distributed compliances is raised as a new problem.

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Documento generato il 24/11/20 alle ore 22:23:43