Advanced

Depolarization Changes During Acute Myocardial Ischemia by Evaluation of QRS Slopes: Standard Lead and Vectorial Approach

Romero, Daniel; Ringborn, Michael LU ; Laguna, Pablo; Pahlm, Olle LU and Pueyo, Esther (2011) In IEEE Transactions on Biomedical Engineering 58(1). p.110-120
Abstract
Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward (I-US) and downward (I-DS) slopes of the R wave as well as the upward (I-TS) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of I-US, I-DS, and I-TS that incorporates dynamic... (More)
Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward (I-US) and downward (I-DS) slopes of the R wave as well as the upward (I-TS) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of I-US, I-DS, and I-TS that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that I-US, I-DS, and I-TS present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change (R-I) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for I-US and I-DS, respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The I-TS index presented a similar behavior to that of I-DS. The timing for the occurrence of significant changes in I-US and I-DS varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative I-DS changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Depolarization, ischemia, percutaneous coronary intervention (PCI), QRS, slopes
in
IEEE Transactions on Biomedical Engineering
volume
58
issue
1
pages
110 - 120
publisher
IEEE--Institute of Electrical and Electronics Engineers Inc.
external identifiers
  • wos:000285515500015
  • scopus:79551537937
ISSN
0018-9294
DOI
10.1109/TBME.2010.2076385
language
English
LU publication?
yes
id
a4456f37-59d1-49c3-bbd4-1354bb27978a (old id 1791101)
date added to LUP
2011-03-02 14:31:53
date last changed
2017-07-23 04:26:39
@article{a4456f37-59d1-49c3-bbd4-1354bb27978a,
  abstract     = {Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward (I-US) and downward (I-DS) slopes of the R wave as well as the upward (I-TS) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of I-US, I-DS, and I-TS that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that I-US, I-DS, and I-TS present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change (R-I) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for I-US and I-DS, respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The I-TS index presented a similar behavior to that of I-DS. The timing for the occurrence of significant changes in I-US and I-DS varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative I-DS changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.},
  author       = {Romero, Daniel and Ringborn, Michael and Laguna, Pablo and Pahlm, Olle and Pueyo, Esther},
  issn         = {0018-9294},
  keyword      = {Depolarization,ischemia,percutaneous coronary intervention (PCI),QRS,slopes},
  language     = {eng},
  number       = {1},
  pages        = {110--120},
  publisher    = {IEEE--Institute of Electrical and Electronics Engineers Inc.},
  series       = {IEEE Transactions on Biomedical Engineering},
  title        = {Depolarization Changes During Acute Myocardial Ischemia by Evaluation of QRS Slopes: Standard Lead and Vectorial Approach},
  url          = {http://dx.doi.org/10.1109/TBME.2010.2076385},
  volume       = {58},
  year         = {2011},
}