Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 2
pubmed:dateCreated
1997-3-31
pubmed:abstractText
Vasodilation of microvessels distal to a stenosis results in an increase in myocardial blood volume (MBV). The purpose of this study was to examine the changes in MBV induced by graded coronary artery stenoses by using myocardial contrast echocardiography (MCE). Accordingly, 21 dogs underwent progressive stenosis of a coronary artery in a random order, the severity of which was judged by the pressure distal to it. Total myocardial blood flow (MBF) to the bed distal to the artery (both anterograde and collateral) was measured by injection of radiolabeled microspheres into the left atrium. In seven dogs, anterograde and total MBF were measured at each stenosis stage by injection of different microspheres into the left atrium and directly into the coronary artery, respectively. MBV was calculated by dividing MBF by the mean transit rate of microbubbles injected directly into the coronary artery during MCE. The perfusion bed size of the artery was also measured by MCE. Our major findings are as follows: 1) there is a nonlinear increase in MBV with increasing degrees of coronary stenosis until the coronary stenosis becomes critical; 2) at moderate levels of coronary stenosis, MBV remains constant despite ongoing autoregulation because of reduction in the size of the perfusion bed supplied by the stenotic vessel; and 3) after exhaustion of autoregulation, a decrease in MBV is noted with increasing levels of stenosis. We conclude that assessment of MBV provides insights into myocardial perfusion distal to a coronary stenosis above and beyond that provided by the measurement of MBF alone.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H567-75
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Changes in myocardial blood volume with graded coronary stenosis.
pubmed:affiliation
Cardiovascular Division, University of Virginia School of Medicine, Charlottesville 22908, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't