| The pressure-flow relation in the canine coronary artery: combined effects of critical stenosis and intracoronary thrombosis. | |
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MedLine Citation:
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PMID: 8595630 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: To characterise the effect of coronary intra-arterial thrombosis upon the downstream vascular bed. BACKGROUND: The vascular response downstream from a coronary intra-arterial thrombus has not previously been characterised. We postulated that downstream vasoconstriction might result from the presence of endothelial damage with consequent growth of platelet-rich thrombus. METHODS: We measured the pressure gradient and flow across, and the pressure/flow ratio distal to, a canine left circumflex artery stenosis with and without endothelial damage causing intracoronary thrombosis. We also observed the effects of transient complete conclusions. RESULTS: At occlusion, the pressure gradient was maximal; relief of occlusion caused a rapid increase flow and distal pressure with a rapid decrease in stenosis pressure gradient and resistance. Subsequently there was a period of stable stenosis resistance with pressure gradient and flow declining; distal pressure therefore increased at this time. Finally in the thrombus group only, stenosis resistance increased again towards re-occlusion. During occlusion, distal pressure averaged 49 +/- 18 mmHg in the presence of thrombus vs. 22 +/- 4 mmHg in its absence (P < 0.001). Following release of occlusion, the flow increased faster than distal pressure, so that the ratio (distal pressure/flow) fell rapidly. Subsequently, distal pressure continued to increase after flow had reached a peak and begun to decline, suggesting vasoconstriction. In the presence of thrombus, the distal pressure/flow ratio was higher than in the absence of thrombus, both at maximal vasodilation (P < 0.005) and at maximum vasoconstriction (P < 0.025). CONCLUSIONS: During cyclic flow variations the stenosis resistance changes are exactly as expected from thrombus growth and embolisation. The distal pressure/flow ratio showed a time-dependent increase which appeared greater when conditions favoured intracoronary thrombosis. |
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Authors:
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P R Belcher; I Vergroesen; A J Drake-Holland; M I Noble |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Cardiovascular research Volume: 30 ISSN: 0008-6363 ISO Abbreviation: Cardiovasc. Res. Publication Date: 1995 Nov |
Date Detail:
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Created Date: 1996-04-18 Completed Date: 1996-04-18 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0077427 Medline TA: Cardiovasc Res Country: NETHERLANDS |
Other Details:
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Languages: eng Pagination: 807-14 Citation Subset: IM |
Affiliation:
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Academic Unit of Cardiovascular Medicine, Charing Cross & Westminster Medical School, London, UK. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure / physiology Coronary Circulation / physiology Coronary Disease / physiopathology* Coronary Thrombosis / physiopathology Coronary Vessels / physiopathology* Dogs Time Factors Vascular Resistance / physiology |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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