Linked Life Data

19931441

Source:http://linkedlifedata.com/resource/pubmed/id/19931441

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-2-22
pubmed:abstractText
During heavy exercise in chronic obstructive pulmonary disease (COPD), dynamic airways compression leads to a progressive fall in intrabreath flow. This is manifested by concavity in the spontaneous expiratory flow-volume (SEFV) curve. We developed a method to quantify the SEFV curve configuration breath-by-breath during incremental exercise utilizing a computerized analysis. The flow signal was digitized at 100Hz. For each breath's SEFV curve, points of highest flow (V (max)) and end-expiration (V (EE)) were identified to define a rectangle's diagonal. Fractional area within the rectangle below the SEFV curve was defined as the "rectangular area ratio" (RAR); RAR <0.5 signifies concavity of the SEFV. To illustrate the utility of this method, time courses of RAR during incremental exercise in 12 healthy and 17 COPD individuals (FEV(1) %Pred.=39+/-12) were compared. SEFV in healthy individuals manifested progressively more convex SEFV curves throughout exercise (RAR=0.56+/-0.08 at rest and 0.61+/-0.05 at peak exercise), but became progressively more concave in COPD patients (RAR=0.52+/-0.08 at rest and 0.46+/-0.06 at peak exercise). In conclusion, breath-by-breath quantification of SEFV curve concavity describes progressive shape changes denoting expiratory flow limitation during incremental exercise in COPD patients. Further studies are warranted to establish whether this novel method can be a reliable indicator of expiratory flow limitation during exercise and to examine the relationship of RAR time course to the development of dynamic hyperinflation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1532-3064
pubmed:author
pubmed:copyrightInfo
Copyright 2009 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
104
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
389-96
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Breath-by-breath quantification of progressive airflow limitation during exercise in COPD: a new method.
pubmed:affiliation
Rehabilitation Clinical Trials Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Validation Studies