| Orthostatic hypotension and the role of changes in venous capacitance. | |
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MedLine Citation:
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PMID: 8897400 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We suggest a mechanism by which blood volume changes might explain the hypotension that, after space flight, often accompanies the return to normal gravity. Upon entering microgravity, peripheral veins may collapse and, because of volume redistribution, raise the pressure in the central venous compartment. After some time in space, homeostatic mechanisms may cause volume excretion and reduce the pressure in the central venous compartment to normal values. Upon return to normal gravity, peripheral veins may re-expand and distribute a reduced blood volume into an enlarged space, thus lowering pressure in the central venous compartment. This would reduce cardiac preload, output, and arterial pressure. To prevent this sequence of events, leg cuffs might be inflated before the end of the space flight to allow homeostatic mechanisms to increase blood volume to normal levels. |
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Authors:
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J V Tyberg; D R Hamilton |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Medicine and science in sports and exercise Volume: 28 ISSN: 0195-9131 ISO Abbreviation: Med Sci Sports Exerc Publication Date: 1996 Oct |
Date Detail:
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Created Date: 1997-03-19 Completed Date: 1997-03-19 Revised Date: 2004-11-17 |
Medline Journal Info:
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Nlm Unique ID: 8005433 Medline TA: Med Sci Sports Exerc Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: S29-31 Citation Subset: IM; S |
Affiliation:
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Department of Medicine, University of Calgary, Alberta, Canada. jtyberg@cvr.ucalgary.ca |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Blood Circulation Blood Volume Humans Hypotension, Orthostatic / physiopathology* Leg / blood supply Space Flight* Vascular Capacitance* Veins / physiology Weightlessness* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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