Linked Life Data

6499147

Source:http://linkedlifedata.com/resource/pubmed/id/6499147

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1984-12-28
pubmed:abstractText
At the clinical level, coronary stenoses frequently behave as though the obstruction to flow were variable and not as rigidly fixed as previously imagined. Pressure (energy) lost in flow through a stenosis is the primary determinant of its hemodynamic impact. Ischemic episodes occur when pressure distal to the stenosis falls below that needed to perfuse the subendocardium. Three important properties of the stenosis contribute to variation in its pressure loss. First, loss is proportional to the square of stenosis flow. Thus proper distribution of perfusion is doubly vulnerable to conditions such as exercise, anemia, or pharmacologic vasodilation, which ordinarily increase myocardial blood flow. Second, pressure loss is proportional to the inverse fourth power of minimum lumen diameter. As a result, seemingly small changes in diameter are amplified to large changes in stenosis resistance. Third, a compliant arc of normal arterial wall borders part of the lumen in the majority of coronary lesions. This extremely important morphologic feature of stenoses permits transient variation in stenosis lumen diameter in response to drugs or to variation in endogenous vasomotor activity or intraluminal pressure. Although our understanding is incomplete, many of the clinical features of coronary disease and its pharmacologic responses are explained in terms of these stenosis properties and their interaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0009-7322
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
917-22
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Dynamic mechanisms in human coronary stenosis.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't