Linked Life Data

10414896

Source:http://linkedlifedata.com/resource/pubmed/id/10414896

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-9-3
pubmed:abstractText
The present study evaluates the use of intracoronary velocity measurements by Doppler guidewires for assessing coronary obstructions. In vitro experiments were performed in a flow model using acrylic phantoms of coronary stenoses with different configurations (stenosis area: 56%, 75% and 89%; stenosis length: 1 and 5 mm; stenosis border: tapering or abrupt). Nonpulsatile laminar flow conditions of a test fluid were established at flow rates ranging from 0.5 to 2.0 mL/s to simulate baseline flow and flow after vasodilation. Peak Doppler velocity was measured proximal to, within and distal to the model stenoses. Computer simulations were employed to calculate radial flow profiles with and without a Doppler wire aligned with the vessel center. In 84 in vitro flow experiments, peak Doppler velocity correlated well with the average flow velocity as calculated from the actual flow rate and the vessel's cross-sectional area proximal to (r = 0.98, SEE = 1.4, p < 0.001) and within (r = 0.97, SEE = 16.4, p < 0.001) the stenosis. However, the ratio of calculated average velocity to Doppler-measured peak velocity was significantly different from 0.5, the expected value for a parabolic flow profile (0.76+/-0.08, 0.81+/-0.14; p < 0.001). Acceptable accuracy was found for the Doppler estimation of stenosis severity using the continuity equation (error: 0.9+/-1.2% and -4.6+/-3.5% for stenosis with a length of 5 mm and 1 mm, respectively). Doppler velocity reserve significantly underestimated the true flow reserve for the 56% and 75% stenoses (p < 0.01). Computer simulations demonstrated significant alterations of flow profiles by the wire, which explained the observed underestimation of the true flow reserve by the Doppler velocity reserve. Thus, Doppler guidewire measurements of intracoronary flow velocities are useful to assess the severity of coronary stenoses. However, the in vitro results and computer simulations indicate that guidewires alter the flow profile, so that Doppler velocity reserve may underestimate the true flow reserve.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0301-5629
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
793-801
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Assessment of coronary stenoses by Doppler wires: a validation study using in vitro modeling and computer simulations.
pubmed:affiliation
Ludwig Boltzmann Research Institute for Cardiac Surgery, University of Vienna, Austria. gporenta@pop3.kard.akh-wien.ac.at
pubmed:publicationType
Journal Article, In Vitro