Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-12-18
pubmed:abstractText
Orthostatic intolerance occurs commonly after spaceflight, and important aspects of the underlying mechanisms remain unclear. We studied 14 individuals supine and standing before and after three space shuttle missions of 9-14 days. After spaceflight, 9 of the 14 (64%) crew members could not complete a 10-min stand test that all completed preflight. Pre- and postflight supine hemodynamics were similar in both groups except for slightly higher systolic and mean arterial pressures preflight in the finishers [15 +/- 3.7 and 8 +/- 1.2 (SE) mmHg, respectively; P < 0.05]. Postflight, finishers and nonfinishers had equally large postural reductions in stroke volume (-47 +/- 3.7 and -48 +/- 3.3 ml, respectively) and increases in heart rate (35 +/- 6.6 and 51 +/- 5.2 beats/min, respectively). Cardiac output during standing was also similar (3.6 +/- 0.4 and 4.1 +/- 0.3 l/min, respectively). However, the finishers had a greater postflight vasoconstrictor response with higher total peripheral resistance during standing (22.3 +/- 1.2 units preflight and 29.4 +/- 2.3 units postflight) than did the nonfinishers (20.1 +/- 1.1 units preflight and 19.9 +/- 1.4 units postflight). We conclude that 1) the primary systemic hemodynamic event, i.e., the postural decrease in stroke volume, was similar in finishers and nonfinishers and 2) the heart rate response and cardiac output during standing were not significantly different, but 3) the postural vasoconstrictor response was significantly greater among the finishers (P < 0.01).
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7-18
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Orthostatic intolerance after spaceflight.
pubmed:affiliation
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-9034, USA.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't