| Studies of the effects of hypothermia on regional myocardial blood flow and metabolsim during cardiopulmonary bypass. II. Ischemia during moderate hypothermia in continually perfused beating hearts. | |
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MedLine Citation:
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PMID: 831013 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The effect of varying perfusion pressure on the adequacy and distribution of coronary flow was studied in normothermic and hypothermic beating hearts. At 37 degrees C., lowering perfusion pressure from 100 to 50 mm. Hg did not change oxygen uptake or total or regional coronary flow or cause biochemical or histochemical ischemia. Vasodilator reserve capacity, however, was expended in order to maintain adequate subendocardial perfusion. At 28 degrees C., myocardial oxygen uptake per minute fell but oxygen consumption per beat rose significantly. Reduction of perfusion pressure to 50 mm. Hg caused a 44 percent (p less than 0.01) reduction in subendocardial flow and resulted in redistribution of flow away from the subendocardium (endocardial/epicardial flow ratio fell from 1.25 to 1.0). Ischemia was evident from intracavitary electrocardiogram, abnormal glycolysis, and histochemical staining. These studies show that during normothermia the coronary arteries dilate to provide adequate coronary flow when perfusion pressure is reduced. In contrast, compensatory vasodilatation is inadequate in hypothermic hearts and ischemia occurs at low perfusion pressures. |
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Authors:
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D H McConnell; J R Brazier; N Cooper; G D Buckberg |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
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Title: The Journal of thoracic and cardiovascular surgery Volume: 73 ISSN: 0022-5223 ISO Abbreviation: J. Thorac. Cardiovasc. Surg. Publication Date: 1977 Jan |
Date Detail:
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Created Date: 1977-02-26 Completed Date: 1977-02-26 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0376343 Medline TA: J Thorac Cardiovasc Surg Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 95-101 Citation Subset: AIM; IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cardiopulmonary Bypass* Coronary Circulation* Coronary Disease / etiology*, metabolism, physiopathology Dogs Electrocardiography Heart Ventricles / metabolism Hypothermia, Induced* Lactates / metabolism Myocardium / metabolism* Oxygen Consumption |
| Chemical | |
Reg. No./Substance:
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0/Lactates |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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