This ECG shows signs of diffuse subendocardial ischemia/infarction in a 62-year-old man with chest tightness and risk factors of diabetes, hypertension, and kidney disease. The ECG findings include left axis deviation, ST segment depression in multiple leads, and ST elevation in leads aVR and V1, suggesting involvement of the left main coronary artery or proximal LAD and LCx arteries. Cardiac enzymes were elevated. Coronary angiography revealed significant stenoses of the left main, LAD, LCx, and RCA arteries consistent with triple vessel disease.

1. RJS ECG Case Series
Case 4

2. RJS ECG Case Series
Interpretation
Sinus rhythm at 85/min with left axis deviation.
Wide spread ST segment depression involving leads II, III,
aVF, and V2-V6 (with associated T wave inversion in leads
III, aVF, and V3-V6).
ST segment elevation in leads aVR and V1.
Taken together, these finding are suggestive of diffuse
subendocardial myocardial ischemia/infarction (NSTEMI)
With the lead aVR showing elevation of the ST segment,
the presence of a significant lesion in the left main coronary
artery or its equivalent (critical lesions in the proximal portion of both
LAD and LCx) should be entertained. In addition, due to inferior lead
involvement, RCA is likely to be also affected.

3. Brief Hx and Physical Findings
This 62-yr-old man was brought to the ER because of having severe
chest tightness of sudden onset, lasting for about 30 min. Reportedly,
he had experienced intermittent episodes of chest tightness like this
one not related to exertion for one year. About one week before this
admission, the frequency of these episodes had increased from 2-3 to
4-5/week.
Past medical Hx was significant for DM and hypertension for more
than 10 years and ESRD presumably due to diabetic nephropathy for
which he had been on peritoneal dialysis for one and a half years.
Additionally, he had one episode of TIA that had occurred
approximately one year prior. On PE, he was obese, in no respiratory
distress. BP measured 110/70 mmHg, PR 80/min and regular, and RR
16/min. The lungs were clear. The PMI of the heart was not visible.
There was a loud S4 but there were no murmurs.

4. Chest X-ray
There is no significant cardiomegaly.
The lung markings are slightly increased
in both lower lung fields.
Bilateral costophrenic angles are clearly
identified.

5. Pertinent Laboratory Data
Cardiac Enzymes
CK CKMB Troponin -I
4/22 165 10.0 0.41
20:28
4/22 252 21.5 8.5
23:59

6. Cardiac Catheterization with Coronary
Artery Angiography
Preserved LV systolic function without significant regional
wall motion abnormality LM ostium: 30-40% narrowing;
LAD-mid: 100% stenosis; LCX-proximal: 80% stenosis, LCx-
m: 80% stenosis, LCx-OM1: 80% stenosis; RCA-m: 90%
stenosis, RCA-PDA: 90% stenosis.

7. Mechanism of ST-segment Elevation in aVR
Lead aVR is referred to as the cavitary lead, electrically
opposite to leads I, II, aVL and V4-6; ST elevation (STE) in
aVR may therefore represent a reciprocal change in
response to ST depression in these leads. Additionally,
Lead aVR also directly records electrical activities from
the RV outflow tract and the basal portion of the
interventricular septum. Consequently, STE in aVR can
result from (a) diffuse subendocardial ischaemia
(reciprocal change) or transmural ischaemia/infarction of
the basal interventricular septum (e.g. due to a proximal
occlusion within the left coronary artery system)

8. Take-Home Message
• The ECG findings suggestive of significant LMCA are
widespread horizontal ST depression, most prominent
in leads I, II and V4-6; ST elevation in aVR ≥ 1mm; and
ST elevation in aVR ≥ V1.
• However, ST elevation in aVR is not entirely specific to
LMCA occlusion. It may also be seen with proximal
LAD occlusion and severe triple vessel CAD.
• ST elevation in aVR ≥ 1 mm is a strong predictor of
severe LMCA /triple vessel CAD requiring CABG.
Kosuge M, et al. An early and simple predictor of severe left main and/or
three-vessel disease in patients with non-ST-segment elevation
acute coronary syndrome. Am J Cardiol. 107:495-500, 2011.

9. Acknolwledgment
The Case was provided by Int 王昇元 / VS 張盛
雄 at MacKay Memorial Hospital, Taipei
2012-04-28