Optimized electrocardiographic criteria for prior inferior and anterior
Robert A. Warner, MD,
Norma E. Hill, RN
Tigard Research Institute, Tigard, OR, USA
Received 26 September 2011
Abstract Background and Purpose: The first purpose of the study was to optimize empirically the detection
of prior inferior myocardial infarction (IMI) and prior anterior myocardial infarction (AMI) by
electrocardiogram (ECG). The second purpose was to compare the diagnostic performances of the
new criteria with those of 3 widely used commercial diagnostic ECG algorithms.
Materials and Methods: We analyzed the digital ECG data from 1138 subjects with suspected
coronary artery disease in whom the presence or absence of prior IMI or AMI was documented by
coronary angiography and left ventriculography. We used receiver operating characteristic curves to
develop the new criteria for prior IMI and AMI using a training set of 562 subjects and then tested
their diagnostic performances using a separate test set of 576 subjects. In both the training and test
sets, we used χ
test to compare the performances of the new criteria with those of 3 commercial
computerized diagnostic algorithms.
Results: The best criterion for prior IMI was the algebraic sum of the Q and T amplitudes in leads III
and aVF. Its sensitivities/specificities were 71%/98% and 74%/98% in the training and test sets,
respectively. The best criterion for prior AMI was the algebraic sum of the Q, R, and T amplitudes
minus the Q duration in leads V
, and V
Its sensitivities/specificities were 68%/98% and 65%/98% in the training and test sets, respectively.
In both the training and test sets, these diagnostic performances were generally superior to those of
the 3 commercial algorithms.
Conclusions: Using digital ECG data, we developed and tested new criteria for prior IMI and AMI
whose diagnostic performances are generally superior to each of 3 widely used commercial ECG
© 2012 Elsevier Inc. All rights reserved.
Keywords: ECG; Prior MI; Diagnostic criteria
The correct diagnosis of prior myocardial infarction (MI)
constitutes prima facie evidence of underlying coronary
artery disease. Failure to reliably detect prior MI impairs risk
stratification and the use of appropriate therapeutic and
preventative strategies. The electrocardiogram (ECG) plays
an important role in the detection of prior MI because it is a
widely used noninvasive test that can be used to identify
coronary artery disease in large numbers of subjects.
However, studies have shown that traditional Q-wave criteria
for prior MI have limited sensitivity and specificity.
Therefore, the purpose of our study was to optimize the
ECG's ability to detect prior MI.
The ECG diagnosis of MI is based on the propensity of an
MI to alter the ECG signal that is recorded in a plane
appropriate for the MI's anatomical location. For example,
an MI in the anterior left ventricular wall tends to alter the
ECG waveforms recorded by the “anterior” ECG leads V
Similarly, an MI in the inferior left ventricular
wall tends to alter the ECG waveforms in the “inferior” ECG
leads II, III, and aVF.
However, the specific ECG leads
that are altered the most by prior MI vary among individual
subjects. For instance, among subjects with prior anterior MI
(AMI), some might exhibit the most significant ECG
abnormalities in lead V
, others in lead V
, still others in
some combination of V
, and so on. Furthermore, the
specific ECG parameters that are altered by prior MI vary
substantially. Depending on the individual subject, the major
Available online at www.sciencedirect.com
Journal of Electrocardiology 45 (2012) 209 – 213
Corresponding author. Tigard Research Institute, 12228 SW Chandler
Drive, Tigard, OR 97224.
E-mail address: email@example.com
0022-0736/$ – see front matter © 2012 Elsevier Inc. All rights reserved.