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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-7-3
pubmed:abstractText
The aim of this study was to analyze the dynamic changes of QT interval--heart rate relation during exercise, fitting their reciprocal variations to an exponential formula (QT = A - B.exp(-k.RR], in order to see whether diagnostic contributions might so be derived. The authors studied 139 patients who underwent a simultaneous assessment of regional myocardial perfusion and ventricular function by means of two injections of 99mTc-methoxy-isobutyl-isonitrile at rest and at peak of a submaximal exercise test, using first pass radionuclide angiography with multielement gamma-camera and single photon emission computerized tomography, in order to detect and localize the presence of stress-induced myocardial ischemia. According to radionuclide results, patients were divided into three groups: group A, 7 individuals with no sign of stress-induced myocardial ischemia; group B, 79 patients with evidence of ischemia in 1 (16.5%), 2 (65.5%), or 3 (17.7%) main coronary territories; and group C, 53 patients with previous infarction and evidence of ischemia in other territories. Conventional analysis of the exercise test (greater than or equal to 0.1 mV ST depression) showed a pathological response in no individual of group A, in 34 patients of group B (43%), and in 27 patients of group C (50.9%); overall sensitivity was 46.2%, specificity 100%, and diagnostic accuracy 48.9%. Exponential coefficients A, B, and k showed wide overlap of values among the three groups, although a significant difference was present in mean k values between groups A and B (p less than 0.001), and group C (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-0736
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
145-53
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Exponential fit of QT interval-heart rate relation during exercise used to diagnose stress-induced myocardial ischemia.
pubmed:affiliation
Second Department of Cardiology, University La Sapienza, School of Medicine, Rome, Italy.
pubmed:publicationType
Journal Article