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Significance of dobutamine-induced changes in QT dispersion early after acute myocardial infarction
- Source :
- The American journal of cardiology. 88(9)
- Publication Year :
- 2001
-
Abstract
- This study sought to examine the effects of graded dobutamine infusion on QT dispersion early after acute myocardial infarction (AMI) and to investigate the relation of dobutamine-induced changes in QT dispersion to wall motion responses. Seventy-eight patients with a first AMI underwent dobutamine-atropine stress echocardiography 5 +/- 2 days after admission. Contractile reserve was identified in 45 patients and ischemic myocardium in 40. Sixteen patients had persistent akinesia. The best cut-off value of QT dispersion on the baseline electrocardiogram for predicting myocardial viability was 65 ms (sensitivity and specificity of 68%). Dobutamine infusion increased QT dispersion only in patients with viable myocardium (61 +/- 18 to 83 +/- 19 ms, p = 0.003) and/or ischemia (72 +/- 16 to 112 +/- 25 ms, p0.0001). No change was observed in patients with persistent akinesia (84 +/- 10 to 87 +/- 15 ms, p = NS). QT dispersion increased by 22 +/- 12 ms with administration of low-dose dobutamine in patients who had viable myocardium and by 47 +/- 21 ms with administration of low- to high-dose dobutamine in patients with ischemic myocardium. An increase in QT dispersion ofor = 20 ms from at rest to low-dose dobutamine infusion was associated with myocardial viability with a sensitivity of 78% and a specificity of 79%, whereas an increase in QT dispersion ofor = 10 ms from low- to high-dose dobutamine infusion predicted ischemic myocardium with a sensitivity of 85% and a specificity of 82%. In conclusion, (1) low QT dispersion on the baseline electrocardiogram is determined by the presence of viable myocardium, (2) a dobutamine-induced increase in QT dispersion is associated with viable and jeopardized myocardium, and (3) unchanged QT dispersion during dobutamine stress is a simple marker of extensive necrosis.
- Subjects :
- Adult
Male
medicine.medical_specialty
Cell Survival
Ischemia
Myocardial Infarction
QT interval
Heart Conduction System
Internal medicine
Dobutamine
medicine
Stress Echocardiography
Humans
Myocardial infarction
Aged
medicine.diagnostic_test
business.industry
Myocardium
Adrenergic beta-Agonists
Middle Aged
medicine.disease
Pathophysiology
Atropine
Anesthesia
Cardiology
Female
Cardiology and Cardiovascular Medicine
business
Electrocardiography
medicine.drug
Echocardiography, Stress
Subjects
Details
- ISSN :
- 00029149
- Volume :
- 88
- Issue :
- 9
- Database :
- OpenAIRE
- Journal :
- The American journal of cardiology
- Accession number :
- edsair.doi.dedup.....816e81fc0d8b167578c2e1c62e9dcc05