| Clinical evidence for myocardial derecruitment downstream from severe stenosis: pressure-flow control interaction. | |
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MedLine Citation:
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PMID: 11087216 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To verify the interaction between coronary pressure (CP) and blood flow (CBF) control, we studied nine candidates for angioplasty of an isolated lesion of the left anterior descending coronary artery [i.e. , percutaneous transluminal coronary angioplasty (PTCA)]. CBF (i.e., flow velocity x coronary cross-sectional area at the Doppler tip) and CP were monitored during washout of 2-5 mCi of (133)Xe after bolus injection into the left main artery before and after PTCA. Xe mean transit time (MTT) was calculated as the area under the time-activity curve, acquired by a gamma camera, divided by the dose obtained from a model fit of the Xe curve in the anterior wall. CBF response to intracoronary adenosine (2 mg) was also assessed. PTCA increased baseline CBF (from 14.5 +/- 9.4 to 20 +/- 8 ml/min, P < 0.01), coronary flow reserve (from 1.52 +/- 0.24 to 2.33 +/- 0.8, P < 0.01), and CP (from 64 +/- 9 to 100 +/- 10 mmHg, P < 0.05). MTT decreased from 89 +/- 32 to 70 +/- 19 s (P < 0.05) after PTCA; however, MTT and CBF changes were not correlated (r = -0.09, not significant). Inasmuch as MTT is the ratio of distribution volume to CBF, MTT x CBF was used as an index of perfused myocardial volume. Volume increased after PTCA from 23 +/- 18 to 56 +/- 30 ml. A direct correlation was observed between the percent increase in distal CP and percent increase in perfused volume (r = 0.91, P < 0.01). Thus low CP was not associated with exhaustion of flow reserve but, rather, with reduction of perfused myocardial volume. These data suggest that, in the presence of a severe coronary stenosis, derecruitment of vascular units occurs that is proportional to the decrease in driving pressure. Residual perfused units maintain a vasomotor tone, thus explaining the paradoxical persistence of coronary reserve. |
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Authors:
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G Sambuceti; M Marzilli; A Mari; C Marini; P Marzullo; R Testa; I Raugei; M Papini; M Schluter; A L'Abbate |
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Publication Detail:
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Type: Clinical Trial; Journal Article |
Journal Detail:
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Title: American journal of physiology. Heart and circulatory physiology Volume: 279 ISSN: 0363-6135 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2000 Dec |
Date Detail:
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Created Date: 2000-12-15 Completed Date: 2000-12-28 Revised Date: 2004-11-17 |
Medline Journal Info:
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Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: H2641-8 Citation Subset: IM |
Affiliation:
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Consiglio Nazionale delle Ricerche Institute of Clinical Physiology, Pisa 56100, Italy. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Angioplasty, Transluminal, Percutaneous Coronary* Aorta / physiology Blood Pressure / physiology* Constriction, Pathologic / physiopathology, therapy, ultrasonography Coronary Angiography Coronary Circulation / physiology* Coronary Disease / physiopathology*, therapy*, ultrasonography Echocardiography, Doppler Homeostasis / physiology Humans Microcirculation / physiology Middle Aged Muscle, Smooth, Vascular / physiology |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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