@article{3051832,
    title = "QRS prolongation on the signal-averaged electrocardiogram versus
ST-segment changes on the 12-lead electrocardiogram: Which is the most
sensitive electrocardiographic marker of myocardial ischemia?",
    author = "Michaelides, AP and Dilaveris, PE and Psomadaki, ZD and Richter, DJ and and Andrikopoulos, GK and Pitsilides, N and Dounis, V and Stefanadis, C and and Toutouzas, PK",
    journal = "Clinical Cardiology",
    year = "1999",
    volume = "22",
    number = "6",
    pages = "403-408",
    publisher = "CLINICAL CARDIOLOGY PUBL CO",
    issn = "0160-9289, 1932-8738",
    doi = "10.1002/clc.4960220607",
    keywords = "QRS prolongation; ST-segment changes; myocardial ischemia; coronary
artery disease",
    abstract = "Background ST-segment changes and QRS prolongation are
electrocardiographic (ECG) markers of myocardial ischemia.
Hypothesis: This study was undertaken to investigate the appearance of
QRS duration changes with or without concomitant ST-segment changes
during a typical anginal episode.
Methods: For this purpose, 126 patients underwent 12-lead surface ECG
and signal-averaged electrocardiogram (SAECG) during typical anginal
pain as well as at the time the patient was asymptomatic. In both
periods, QRS duration and ST-segment changes were evaluated. All
patients underwent cardiac catheterization.
Results: Of the 126 patients, 108 (86%) had coronary artery disease
(CAD), whereas the remaining 18 (14%) patients had normal coronary
arteriograms. During typical anginal pain, 75 of the 108 (70%) patients
with CAD and 2 of the 18 (11%) patients with normal coronary
arteriograms developed QRS prolongation, whereas 60 of the 108 (56%)
patients with CAD and 2 of the 18 (11%) patients with normal coronary
vessels developed ST-segment changes. Thus, the sensitivities of QRS
prolongation measured by SAECG and of ST-segment changes on the surface
ECG for the detection of myocardial ischemia were found to be 70 and
56%, respectively, (p < 0.01), whereas the specificities were both
found to be 89% (p = NS).
Conclusions: During typical anginal pain, QRS prolongation on the SAECG
is more sensitive than are ST-segment changes on the ECG for the
detection of myocardial ischemia."
}