Document Detail


Pressure-flow characteristics of the coronary collaterals: a model study.
MedLine Citation:
PMID:  8304513     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The pressure-flow relationship of the coronary collaterals is investigated by using an electrical analog model that combines the coronary epicardial arteries with the nonlinear characteristics of the intramyocardial circulation. The study aims to examine some controversial issues concerning the collateral circulation, including the transmural distribution of the collaterals, the distensibility of the collateral vessels (whether rigid or complaint), the effects of microcirculatory embolization, the collateral zero-flow pressure, and the nonlinearity of the collateral pressure-flow relationship. The study is carried out by simulating and comparing two basic experimental set-ups in which a coronary artery is ligated and the retrograde flow serves as an index of collateral flow. In the first "free-flow" setup, flow is allowed to bleed retrogradely against atmospheric pressure while perfusion pressure to the rest of the coronary arteries is varied over a wide range. In the second "back-pressure" setup, the coronary perfusion pressure is maintained at the control levels while the back pressure to the retrograde flow in the excised artery is varied. According to the analysis, the nonlinear pressure-flow relationships depend heavily on the experimental setup and are a function of the distensibility of the collaterals, which are distributed mainly on the epicardial surface, and the nonlinear contraction characteristics of the myocardium. The measured retrograde flow tends to underestimate the total collateral flow for the back-pressure setup because of antegrade flow escape.
Authors:
D Manor; R Beyar; S Sideman
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  266     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1994 Jan 
Date Detail:
Created Date:  1994-03-09     Completed Date:  1994-03-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H310-8     Citation Subset:  IM    
Affiliation:
Julius Silver Institute, Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure*
Collateral Circulation*
Computer Simulation
Coronary Circulation*
Humans
Models, Cardiovascular*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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