Document Detail


Reduction in QT interval dispersion by successful thrombolytic therapy in acute myocardial infarction. TEAM-2 Study Investigators.
MedLine Citation:
PMID:  8026057     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: QT dispersion (QTd, equals maximal minus minimal QT interval) on a standard ECG has been shown to reflect regional variations in ventricular repolarization and is significantly greater in patients with than in those without arrhythmic events. METHODS AND RESULTS: To assess the effect of thrombolytic therapy on QTd, we studied 244 patients (196 men; mean age, 57 +/- 10 years) with acute myocardial infarction (AMI) who were treated with streptokinase (n = 115) or anistreplase (n = 129) at an average of 2.6 hours after symptom onset. Angiograms at 2.4 +/- 1 hours after thrombolytic therapy showed reperfusion (TIMI grade > or = 2) in 75% of patients. QT was measured in 10 +/- 2 leads at 9 +/- 5 days after AMI by using a computerized analysis program interfaced with a digitizer. QTd, QRSd, JT (QT minus QRS), and JT dispersion (JTd, equals maximal minus minimal JT interval) were calculated with a computer. There were significant differences in QTd (96 +/- 31, 88 +/- 25, 60 +/- 22, and 52 +/- 19 milliseconds; P < or = .0001) and in JTd (97 +/- 32, 88 +/- 31, 63 +/- 23, and 58 +/- 21 milliseconds; P = .0001) but not in QRSd (25 +/- 10, 22 +/- 7, 28 +/- 9, and 24 +/- 9 milliseconds; P = .24) among perfusion grades 0, 1, 2, and 3, respectively. Similar results were obtained comparing TIMI grades 0/1 with 2/3 and 0/1/2 with 3. Patients with left anterior descending (versus right and left circumflex) coronary artery occlusion showed significantly greater QTd (70 +/- 29 versus 59 +/- 27 milliseconds, P = .003) and JTd (74 +/- 30 versus 63 +/- 27 milliseconds, P = .004). Similarly, patients with anterior (versus inferior/lateral) AMI showed significantly greater QTd (69 +/- 30 versus 59 +/- 27 milliseconds, P = .006) and JTd (73 +/- 30 versus 63 +/- 27 milliseconds, P = .007). Results did not change when Bazett's QTc or JTc was substituted for QT or JT or when ANOVA included adjustments for age, sex, drug assignment, infarct site, infarct vessel, and number of measurable leads. On ANCOVA, the relation of QTd or JTd and perfusion grade was not influenced by heart rate. CONCLUSIONS: Successful thrombolysis is associated with less QTd and JTd in post-AMI patients. The results are equally significant when either QT or JT is used for analysis. These data support the hypothesis that QTd after AMI depends on reperfusion status as well as infarct site and size. Reduction in QTd and its corresponding risk of ventricular arrhythmia may be mechanisms of benefit of thrombolytic therapy.
Authors:
F L Moreno; T Villanueva; L A Karagounis; J L Anderson
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Publication Detail:
Type:  Clinical Trial; Journal Article; Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Circulation     Volume:  90     ISSN:  0009-7322     ISO Abbreviation:  Circulation     Publication Date:  1994 Jul 
Date Detail:
Created Date:  1994-08-11     Completed Date:  1994-08-11     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0147763     Medline TA:  Circulation     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  94-100     Citation Subset:  AIM; IM    
Affiliation:
University of Utah School of Medicine, Salt Lake City.
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MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Analysis of Variance
Coronary Angiography
Coronary Circulation
Double-Blind Method
Electrocardiography*
Female
Humans
L-Lactate Dehydrogenase / blood
Male
Middle Aged
Myocardial Infarction / physiopathology*,  radiography,  therapy*
Thrombolytic Therapy*
Chemical
Reg. No./Substance:
EC 1.1.1.27/L-Lactate Dehydrogenase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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