Document Detail


Lack of impact of myocardial ischemia on the signal-averaged ECG assessment by time-domain analysis.
MedLine Citation:
PMID:  12167178     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Late potentials represent an arrhythmogenic substrate in chronically infarcted myocardium. It is hypothesized that acute transient ischemia enhances anisotropic electrical ventricular activation and facilitates reentry mechanisms. Study aim was the prospective assessment of the impact of dipyridamole-induced myocardial ischemia on the signal-averaged ECG. METHODS: Dipyridamole stress thallium-201 SPECT imaging was utilized to avoid noise contamination of the signal-averaged ECG from exercise and to document evidence and localization of myocardial ischemia or persistent perfusion defects in 68 patients with suspected coronary artery disease. Before and during dipyridamole-induced vasodilatation serial signal-averaged ECG was performed to evaluate the influence of transient ischemia on the occurrence of late potentials. RESULTS: There was a significant difference between heart rate at rest and heart rate under dipyridamole influence in patients with inducible ischemia (70 +/- 13 vs. 87 +/- 13; P < 0.0001) in contrast to patients without dipyridamole-induced ischemia (74 +/- 20 vs. 80 +/- 16; n.s.). The number of averaged beats and achieved noise level was comparable between both groups. Thirty-three of 68 patients (49%) revealed dipyridamole-induced ischemia; however, no changes of the SAECG parameters, such as QRS, RMS, LAS at 25-250 and 40-250 Hz bandpass filtering in the leads X, Y, Z and vector magnitude, respectively, were observed as a result of ischemia. CONCLUSION: These results suggest that transient myocardial ischemia does not affect the signal-averaged ECG. Clinically, the signal-averaged ECG analysis seems not to be helpful in identifying patients with silent ischemia.
Authors:
Michael A E Schneider; Christoph A Nienaber
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc     Volume:  7     ISSN:  1082-720X     ISO Abbreviation:  Ann Noninvasive Electrocardiol     Publication Date:  2002 Jul 
Date Detail:
Created Date:  2002-08-08     Completed Date:  2002-10-11     Revised Date:  2008-03-10    
Medline Journal Info:
Nlm Unique ID:  9607443     Medline TA:  Ann Noninvasive Electrocardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  191-7     Citation Subset:  IM    
Affiliation:
German Heart Center, Munich, Germany. SchneiderM@DHM.mhn.de
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MeSH Terms
Descriptor/Qualifier:
Aged
Analysis of Variance
Dipyridamole / diagnostic use
Electrocardiography / methods*
Exercise Test / methods*
Female
Humans
Male
Middle Aged
Myocardial Ischemia / diagnosis*
Probability
Prospective Studies
Sensitivity and Specificity
Severity of Illness Index
Statistics, Nonparametric
Tomography, Emission-Computed, Single-Photon / methods*
Chemical
Reg. No./Substance:
58-32-2/Dipyridamole

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


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