Linked Life Data

9597118

Source:http://linkedlifedata.com/resource/pubmed/id/9597118

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-7-16
pubmed:abstractText
During orthostatic hypotension we evaluated whether presyncopal symptoms relate to a reduced brain oxygenation. Nine subjects performed 50 degrees head-up tilt for 1 h and eight subjects were followed during 2 h of supine rest and during 1 h of 10 degrees head-down tilt. Cerebral perfusion was assessed by transcranial Doppler determined middle cerebral artery blood velocity (MCA vmean), while brain blood oxygenation was assessed by near-infrared spectrophotometry determined concentration changes for oxygenated (delta HbO2) and deoxygenated haemoglobin and brain cell oxygenation by the oxidized cytochrome c concentration (delta CytO2). During head-up tilt, six volunteers developed presyncopal symptoms and mean arterial pressure (88 (78-103) to 68 (57-79) mmHg; median and range), heart rate (96 (72-111) to 65 (50-107) beats min-1), MCA vmean (59 (51-82) to 41 (29-56) cm s-1), delta HbO2 (by -5.3 (-3.0 to -14.8) mumol l-1) and delta CytO2 were reduced (by -0.2 (-0.1 to -0.4) mumol l-1; P < 0.05). During tilt down the cardiovascular variables recovered immediately and delta HbO2 increased to 2.2 (-0.9-12.0) mmol L-1 above the resting value and also delta CytO2 recovered. In the nonsyncopal head-up tilted subjects as in the controls, blood pressure, heart rate, MCA vmean and brain oxygenation indices remained stable. The results suggest that during orthostasis, presyncopal symptoms relate not only to cerebral hypoperfusion but also to reduced brain oxygenation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0001-6772
pubmed:author
pubmed:issnType
Print
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
501-7
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Near-infrared spectrophotometry determined brain oxygenation during fainting.
pubmed:affiliation
Copenhagen Muscle Research Centre, Department of Anaesthesia, Rigshospitalet, University of Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't