Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-4-13
pubmed:abstractText
The ECG is routinely used in many species to monitor effects of drugs. While it is relatively easy to measure both PR and QRS, measurement of QT is complicated by the fact that this interval can change with heart rate. In order to compensate for variations in QT due to variations in heart rate, various correction factors have been used, including those of Bazett and Hodges. Such corrections were devised for humans and may have limited applicability in other species. We have systematically varied heart rate in anesthetized rats, guinea pigs, rabbits, and primates using procedures such as vagal stimulation, direct atrial stimulation, injection of cold saline and drugs, including anesthetics, and measured the resulting QT (as QaT and related measures). Over a wide range of heart rates we tested various formulas for their value in correcting for the variation in QT interval associated with changes in heart rate. In rats the "QT" interval did not change appreciably with heart rate. In the other species QaT intervals varied in the expected manner with heart rate in that they decreased with tachycardia and increased with bradycardia. Various formulas were tested for their utility in correcting measures of the QaT interval (QaTc) for changes in heart rate in guinea pigs, rabbits, and primates. In species other than rats, there was little difference between the various formulas in their ability to increase the precision of QaTc and the normality of its distribution, although the best correction is that derived from the regression (either linear, square root, or polynomial) equation relating RR and QaT.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1056-8719
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
201-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Relationship between QaT and RR intervals in rats, guinea pigs, rabbits, and primates.
pubmed:affiliation
Department of Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't