ECG Case 103

53 year old male presenting with central chest pain for 2 hours, ongoing at time of recording

ECG Case 103a LITFL Top 100 EKG

Describe and interpret this ECG



  • ~84 bpm


  • Regular


  • Normal (~75 deg)


  • PR – Normal (200ms)
  • QRS – Normal (100ms)
  • QT – 360ms (QTc Bazett ~ 425 ms)


  • ST Elevation lead aVR ~0.5mm
  • ST Depression
    • Horizontal leads V2-V4
    • Concave leads II, aVF, V5-V6


  • T wave inversion lead V1
  • Flat T waves II, III, aVF, aVL, V5, V6
  • Notching terminal portion QRS complex leads II, V5, V6
  • R/S Ratio V2=0.85


Highly suspicious ECG for Posterior STEMI

  • Flat right precordial ST depression
  • Prominent R wave V2, although R/S <1
  • Inferolateral ST depression
  • Patient c/o acute chest pain


The patient had posterior leads (V7-9) performed, ECG below.

You can see leads V1 & V3 have been moved to the posterior region and re-labelled as V7 & V9. This configuration is due to our local lead set up which uses only two physical leads with multiple connectors on each to record the twelve lead.

As you can see there is ST elevation in lead V7 (1mm) and V9 (~0.5mm) which is diagnostic of an isolated posterior infarction.

The patient was transferred for urgent coronary angiography & PCI.

His angiography showed:

  • Left main – irregularities
  • Left anterior descending – 40-50% mid vessel stenosis
  • Left circumflex – proximal occlusion
  • Right coronary – proximal occlusion with bridging collaterals
  • Ventriculogram – normal

His proximal circumflex lesion was stented acutely, and he was discharged following a 4 day in-patient stay.


Mirror Test

Well with a paper ECG you turn it upside down and look through the back of the ECG. Through the magic of computer technology we can do the same with our ECG here, image below.

We can now see ST elevation in these leads with a deep Q and negative T wave similar to the actual posterior lead morphology.

I would recommend people have a read of the great post on EMS 12-Lead blog about these morphology changes as they raise several excellent points about the traditional morphological diagnostic criteria for posterior STEMI.  

More on Posterior STEMI

TOP 150 ECG Series

Emergency Medicine Specialist MBChB FRCEM FACEM. Medical Education, Cardiology and Web Based Resources | @jjlarkin78 | LinkedIn |

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