Linked Life Data

10532638

Source:http://linkedlifedata.com/resource/pubmed/id/10532638

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1999-10-29
pubmed:abstractText
This study evaluates the effect of orthostasis on the low frequency (LF, 0.04 to 0.15 Hz) fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV) in relation to its arterial blood pressure (ABP) equivalent to further define and quantify this relationship in cerebrovascular regulation. Spectral analysis was performed on 22 healthy subjects during supine rest and head-up tilt. The power in the LF range can be used to quantify the LF fluctuations, and four types of LF power data could be obtained for each individual: LF power of supine MCAFV, LF power of supine ABP, LF power of tilt MCAFV, and LF power of tilt ABP. By comparing LF power of MCAFV with LF power of ABP, two power ratios could be generated to describe the flow-pressure relationship during supine rest and head-up tilt, respectively, supine power ratio (LF power of supine MCAFV/ LF power of supine ABP) and tilt power ratio (LF power of tilt MCAFV/ LF power of tilt ABP). In addition, an index for dynamic autoregulation in response to orthostasis can be calculated from these two power ratios (tilt power ratio/supine power ratio). The authors found that this index was dependent on the extent of orthostatic MCAFV changes, and the dependency could be mathematically expressed (r = 0.61, P = .0001), suggesting its involvement in cerebrovascular regulation. Moreover, these data further support the previous observation that the LF fluctuations of MCAFV might result from modulation of its ABP equivalent, and the modulation effect could be quantified as the power ratio (LF power of MCAFV/ LF power of ABP). These observations could be an important step toward further insight into cerebrovascular regulation, which warrants more research in the future.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1136-41
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Spectral analysis of arterial blood pressure and cerebral blood flow velocity during supine rest and orthostasis.
pubmed:affiliation
Section of Cerebrovascular Disease, Veterans General Hospital-Taipei, Taiwan, Republic of China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't