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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
7
|
| pubmed:dateCreated |
1996-12-4
|
| pubmed:abstractText |
This study investigated interobserver (two observers) and intrasubject (two measurements) reproducibility of QT dispersion from abnormal electrocardiograms in patients with previous myocardial infarction, and compared a user-interactive with an automatic measurement system. Standard 12-lead electrocardiograms, recorded at 25 mm.s-1, were randomly chosen from 70 patients following myocardial infarction. These were scanned into a personal computer, and specially designed software skeletonized and joined each image. The images were then available for user-interactive (mouse and computer screen), or automatic measurements using a specially designed algorithm. For all methods reproducibility of the RR interval was excellent (mean absolute errors 3-4 ms, relative errors 0.3-0.5%). Reproducibility of the mean QT interval was good; intrasubject error was 6 ms (relative error 1.4%), interobserver error was 7 ms (1.8%), and observers' vs automatic measurement errors were 10 and 11 ms (2.5, 2.8%). However QTc dispersion measurements had large errors for all methods; intrasubject error was 12 ms (17.3%), interobserver error was 15 ms (22.1%), and observers' vs automatic measurement were errors 30 and 28 ms (35.4, 31.9%). QT dispersion measurements rely on the most difficult to measure QT intervals, resulting in a problem of reproducibility. Any automatic system must not only recognize common T wave morphologies, but also these more difficult T waves, if it is to be useful for measuring QT dispersion. The poor reproducibility of QT dispersion limits its role as a useful clinical tool, particularly as a predictor of events.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jul
|
| pubmed:issn |
0195-668X
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
17
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1035-9
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:8809521-Diagnosis, Computer-Assisted,
pubmed-meshheading:8809521-Electrocardiography,
pubmed-meshheading:8809521-Humans,
pubmed-meshheading:8809521-Long QT Syndrome,
pubmed-meshheading:8809521-Myocardial Infarction,
pubmed-meshheading:8809521-Observer Variation,
pubmed-meshheading:8809521-Reproducibility of Results,
pubmed-meshheading:8809521-Sensitivity and Specificity
|
| pubmed:year |
1996
|
| pubmed:articleTitle |
Reproducibility and automatic measurement of QT dispersion.
|
| pubmed:affiliation |
Department of Medicine and Therapeutics, University of Leicester, U.K.
|
| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|