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High frequency QRS electrocardiogram analysis during exercise stress testing for detecting ischemia

Lipton, J. A.; Warren, S. G.; Broce, M.; Beker, A.; Sörnmo, Leif LU ; Lilly, D. R.; Maynard, C; Lucas, D. B. and Wagner, G. (2008) In International Journal of Cardiology 124(2). p.198-203
Abstract
Introduction

ECG stress testing is an inexpensive and non-invasive detector of myocardial ischemia; addition of high-frequency QRS analysis (HFQRS) may improve accuracy. This study compared HFQRS during exercise in patients with and without ischemia as defined by multiple criteria.



Material and methods

High-resolution ECGs were recorded for 139 patients undergoing T99-sestamibi/T201-thallium stress testing. Twenty-three were positive by at least two and 37 were negative for ischemia by all three of the following criteria: nuclear scan, ST-segment analysis and typical angina. Sixty-four not meeting criteria for positive or negative, six with adenosine test and nine patients with ECG recording artifacts... (More)
Introduction

ECG stress testing is an inexpensive and non-invasive detector of myocardial ischemia; addition of high-frequency QRS analysis (HFQRS) may improve accuracy. This study compared HFQRS during exercise in patients with and without ischemia as defined by multiple criteria.



Material and methods

High-resolution ECGs were recorded for 139 patients undergoing T99-sestamibi/T201-thallium stress testing. Twenty-three were positive by at least two and 37 were negative for ischemia by all three of the following criteria: nuclear scan, ST-segment analysis and typical angina. Sixty-four not meeting criteria for positive or negative, six with adenosine test and nine patients with ECG recording artifacts were excluded. Mean age of the study group was 62 ± 10 years, 83% were male. Ischemic patients had a higher incidence of previous myocardial infarction and coronary intervention than non-ischemic patients (74% vs. 46%; P = 0.03 and 70% vs. 43%; P = 0.05, respectively), but had a lower body mass index (28.7 ± 5 vs. 33.0 ± 8; P = 0.015). HFQRS analysis consisting of signal averaging (150–250 Hz) and calculation of root mean squared values for each lead at different time points was performed and was similar between the groups. The relative change in HFQRS (RCQ) was calculated for each lead: {(maxHFQRS − minHFQRS) / maxHFQRS}. For each patient an RCQ index was calculated by averaging the two leads with the greatest RCQ value. The RCQ index was greater in ischemic vs. non-ischemic patients (45% vs. 34%; P = 0.0069).



Conclusion

Maximum decrease in HFQRS, as quantified by RCQ index, was greater in ischemic vs. non-ischemic patients. Use of the RCQ index may improve the diagnosis of ischemia during exercise stress testing. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Cardiology
volume
124
issue
2
pages
198 - 203
publisher
Elsevier
external identifiers
  • wos:000254825100012
  • scopus:38649103452
ISSN
0167-5273
DOI
10.1016/j.ijcard.2007.02.002
language
English
LU publication?
yes
id
095cbadd-3084-4deb-8a1c-0002cd5db407 (old id 1047142)
date added to LUP
2008-03-11 14:17:22
date last changed
2017-01-15 04:22:59
@article{095cbadd-3084-4deb-8a1c-0002cd5db407,
  abstract     = {Introduction<br/><br>
ECG stress testing is an inexpensive and non-invasive detector of myocardial ischemia; addition of high-frequency QRS analysis (HFQRS) may improve accuracy. This study compared HFQRS during exercise in patients with and without ischemia as defined by multiple criteria.<br/><br>
<br/><br>
Material and methods<br/><br>
High-resolution ECGs were recorded for 139 patients undergoing T99-sestamibi/T201-thallium stress testing. Twenty-three were positive by at least two and 37 were negative for ischemia by all three of the following criteria: nuclear scan, ST-segment analysis and typical angina. Sixty-four not meeting criteria for positive or negative, six with adenosine test and nine patients with ECG recording artifacts were excluded. Mean age of the study group was 62 ± 10 years, 83% were male. Ischemic patients had a higher incidence of previous myocardial infarction and coronary intervention than non-ischemic patients (74% vs. 46%; P = 0.03 and 70% vs. 43%; P = 0.05, respectively), but had a lower body mass index (28.7 ± 5 vs. 33.0 ± 8; P = 0.015). HFQRS analysis consisting of signal averaging (150–250 Hz) and calculation of root mean squared values for each lead at different time points was performed and was similar between the groups. The relative change in HFQRS (RCQ) was calculated for each lead: {(maxHFQRS − minHFQRS) / maxHFQRS}. For each patient an RCQ index was calculated by averaging the two leads with the greatest RCQ value. The RCQ index was greater in ischemic vs. non-ischemic patients (45% vs. 34%; P = 0.0069).<br/><br>
<br/><br>
Conclusion<br/><br>
Maximum decrease in HFQRS, as quantified by RCQ index, was greater in ischemic vs. non-ischemic patients. Use of the RCQ index may improve the diagnosis of ischemia during exercise stress testing.},
  author       = {Lipton, J. A. and Warren, S. G. and Broce, M. and Beker, A. and Sörnmo, Leif and Lilly, D. R. and Maynard, C and Lucas, D. B. and Wagner, G.},
  issn         = {0167-5273},
  language     = {eng},
  number       = {2},
  pages        = {198--203},
  publisher    = {Elsevier},
  series       = {International Journal of Cardiology},
  title        = {High frequency QRS electrocardiogram analysis during exercise stress testing for detecting ischemia},
  url          = {http://dx.doi.org/10.1016/j.ijcard.2007.02.002},
  volume       = {124},
  year         = {2008},
}