This document discusses high-risk ECG presentations that do not meet criteria for STEMI but still indicate acute myocardial infarction (AMI). It presents six case studies with ECG patterns including: ST elevation in aVL and V2 indicating D1 lesion; de Winter finding of ST depression in V2-V5 with T waves in V2-V4 indicating proximal LAD occlusion; ST elevation in aVR with widespread ST depression indicating left main coronary artery occlusion; Wellen's syndrome biphasic T waves in V1-V4 indicating proximal LAD occlusion; and ST depression in V2-V4 with tall R waves indicating posterior wall AMI. The document emphasizes that ECGs must be interpreted in clinical context and

1. The Electrocardiogram in the ACS
Patient: High-Risk ECG Presentations
Lacking Anatomically Oriented ST
Segment Elevation
Prepared by:
Dr Sazwan Reezal Bin Shamsuddin
EP HoSHAS

3. Classic
• STEMI is defined as a new ST segment
elevation (STE) at the J point in at least two
anatomically contiguous leads of at least 2mm
(0.2mV) in men or at least 1.5mm in women in
leads V2-V3 and/or of at least 1mm (0.1mV) in
other contiguous leads or the limb leads.

4. Current
• It is now recognized that ECG patterns which do not
meet the traditional diagnostic criteria for STEMI may
represent significant AMI.
• these patterns are generally referred to as the STEMI
equivalent patterns
• they are caused by occlusion of an epicardial coronary
artery, place significant portions of the left ventricle in
jeopardy, and can result in a poor outcome if not
recognized and treated appropriately.
• Fortunately, if recognized promptly, these high-risk ECG
patterns may aid clinicians in identifying lesser known
presentations of AMI or AMI-equivalent patterns.

5. This presentation:
• These patterns are associated with larger AMI
patterns and thus greater risk of poor outcome:
malignant dysrhythmia
cardiogenic shock
stroke
death
worsened post- AMI lifestyle due to greater
cardiac injury.

7. ST segment elevation in
leads aVL and V2
ST segment depression
in leads III and aVF
This ECG pattern is consistent with a first diagonal, or D1, lesion.

9. • The left anterior descending artery (LAD) is
the most commonly identified coronary vessel
occlusion resulting in AMI.
• The first diagonal branch (D1) of the LAD
supplies blood to the anterolateral wall of the
left ventricle as it courses diagonally over
these regions.

10. Figure 1
• male patient presented with severe chest pain and
significant diaphoresis.
• ECG revealed concerning STE in leads aVL and V2 as
well as inferior ST segment depression. The “non-
anatomical ECG presentation” did not meet traditional
diagnostic criteria for STEMI.
• Yet, the doctor interpreted the ECG within the context
of a high-risk presentation, initiating care appropriate
for ACS and urgently consulting cardiology.
• At percutaneous coronary intervention (PCI), a 100%
D1 lesion was noted and stented.

11. ST segment depression with
J point depression in
leads V2 to V5
prominent T waves are noted
in leads V2 to V4
ST segment elevation is seen in lead aVR
This ECG pattern is termed the de Winter finding and is
consistent with a proximal LAD occlusion.

13. • Regardless of its electrophysiologic basis,
its presence in the setting of a patient
• with typical ACS symptoms and signs
should alert the emergency physician to a
highrisk
• presentation.

14. Figure 2
• a 42 year-old male with chest pain
demonstrates ST segment depression with J point
depression in leads V2 to V5
prominent T waves are noted in leads V2 to V4;
ST segment elevation is seen in lead aVR.
• Appropriate therapy including urgent cardiology
consultation was made with urgent PCI.
• A proximal left anterior descending lesion was
noted and successfully stented.

15. lead aVR ST segment elevation
Widespread ST segment depression in leads II, III, aVF, V4, V5, and V6
This pattern of ECG findings is consistent with left main coronary artery
occlusion.

16. lead aVR ST segment elevation
Widespread ST segment depression in leads I, II, III, aVF, and V2 to V6
This pattern of ECG findings is consistent with left
main coronary artery occlusion.

18. • In most instances, the left main coronary
artery (LMCA) supplies approximately 75% of
the left ventricular myocardium as it
bifurcates into the LAD and left circumflex
• acute occlusion of the LMCA is frequently
accompanied by cardiogenic shock,
pulmonary edema, life-threatening
arrhythmias, and sudden cardiac death .

19. • Lead aVR is is frequently ignored during ECG
interpretation,.
• The importance of lead aVR in relation to
LMCA occlusion was initially demonstrated
after a group of investigators hypothesized
that the presence of lead aVR STE in LMCA
occlusion may be due to septal ischemia as
was shown in previous studies of proximal
LAD occlusion.

20. Figures 3 and 4
widespread ST segment depression
ST segment elevation in lead aVR. This
constellation of findings, in the appropriate
patient, can suggest LMCA obstruction.
• Both patients presented with:
concerning chest pain and were extremely ill
appearing on examination.
Based upon the ECG findings, the patients were
taken urgently to PCI with left main coronary
artery lesions noted and appropriately managed

21. biphasic T wave abnormalities
in leads V1 to V4.
Biphasic refers to both upright and inverted T wave abnormalities in a single T wave
Wellen’s syndrome and is consistent with proximal LAD
occlusion.

23. • Wellens’ Syndrome was first described by de
Zwaan et al in 1982 after this group recognized a
specific ECG pattern in patients with unstable
angina who were found to be at high risk for the
development of anterior wall AMI.
The results of this initial study revealed:
• with 75% of those patients who did not undergo
a coronary revascularization procedure
developing an anterior wall AMI within days to
weeks of the

24. The clinical description of Wellens’
Syndrome
1) active (or recent) anginal
chest pain
2) minimal or no cardiac
biomarker elevation
3) absence of pathologic
precordial Q waves
4) minimal or lack of ST
segment elevation (<1mm)
5) no loss of precordial R wave
progression
6) characteristic T-wave
abnormalities.
• The T wave changes, being the
most important diagnostic
feature of Wellens’ Syndrome,
consist of two distinct patterns
in leads V2 and V3.
 The more common
abnormality (75% of cases)
consists of deeply inverted and
symmetric T waves.
 the second subtype consists of
biphasic T waves (25% of
cases)

25. Figure 5
• a patient with recent chest pain presents with
biphasic T-wave abnormalities in the anterior
leads.
• The significance of the ECG findings was noted
by the ED doctors resulting in cardiology
admission and cardiac catheterization which
demonstrated proximal LAD occlusion and
subsequent appropriate stenting.

26. ST segment depression in leads V2 to V4
prominent R waves are noted in leads V2
and V3 along with upright T waves in
leads V2 to V4
These findings are consistent with acute posterior
wall acute myocardial
infarction

28. Posterior MI
• While PMI often occurs in conjunction with
acute lateral and / or inferior infarctions, ECG
manifestations of isolated PMI include the
following:
 in leads V1-V4: 1) horizontal STD; 2)
upright T waves; 3) a tall, wide R wave; 4) an R-
to-S wave ratio of greater than 1.0 in lead V2

29. Figure 6
• 54 year-old female with chest discomfort.
• ECG demonstrates normal sinus rhythm with ST
segment depression in leads V2 to V4.
• prominent R waves are noted in leads V2 and V3
along with upright T waves in leads V2 to V4.
• These findings are recognized as consistent with
acute posterior wall acute myocardial infarction.
• The patient was taken to the catheterization
laboratory with PCI of a distal left circumflex
artery occlusion was successfully stented

31. In Summary
• ECG is important tool to evaluate AMI.
• ED doctors must be able to recognize STEMI
equivalent patterns ECGs.
• All STEMI equivalent patterns ECG need
cardiologist consultation.
• ST Depression may be a fatal ECG.

32. Slide available on SlideShare