ECG of the Week – 26th May 2021 – Interpretation

You have requested an ECG for a 91 year old lady who has multiple co-morbidities and lives in a nursing home. She has presented short of breath. Her ECG is as below.


  • Rate: 114
  • Rhythm: Flutter (easily confused as sinus when looking at anterior leads, flutter waves seen pre QRS and in T wave in lead II)
  • Axis: Normal (0-90)
  • Morphology: 1.5mm STE aVR, 1mm STE V1, subtle 0.5mm STE aVL, widespread 1-2mm downsloping STD (seen in leads II, III, aVF, V3-6) more subtle 1/2mm STD in I
  • Intervals: QRS 80 QT 320 QTc 445 (Bazetts)
  • Summary: An interesting ECG!


ST elevation in aVR and global ST depression elsewhere is highly indicative of diffuse subendocardial ischaemia which is seen in a variety of cases where the oxygen supply and demand are mismatched. Thinking of it in this manner the STE in aVR is essentially a reciprocal change to the left leads of I,II, aVL, V4-6 as it is electrically opposite (remember aVR overlies atria only not myocardial wall)

Causes include

  • LMCA or Proximal LAD stenosis
    • Studies have shown that STE of >= 1.5 mm is associated with  up to 70% mortality
  • Triple vessel disease
  • Hypoxia – eg PE
  • Hypotension – eg post ROSC, blood loss

Implications for Management:

This would depend entirely on this ladies history.

Differentials include:

  • LAD/LMCA stenosis
    • If she had presented with clinical symptoms of MI she should be managed as a STEMI equivalent (whilst taking into consideration her co-morbidites and functional capacity given she is a 91 year old NH resident) The main change in management would be withholding ticagrelor / clopidogrel if she was a candidate for CABG (increased risk of major bleeding)
    • You could also consider this diagnosis given she is elderly (especially if there was a Hx of DM) without CP as a silent MI with or without secondary APO
  • Rate related ischaemia
    • less likely given rate is only 116 but in a 91 year old lady this may be possible
    • Seen especially in AVNRT and flutter
    • Mechanism not entirely known ? rate related supply and demand mismatch vs ‘unofficial stress test’ unmasking of CAD
  • Other causes of SOB causing supply and demand subendocardial ischaemia
    • PE
    • LRTI
    • COPD etc
    • APO

With thanks to Dr Fiona Beattie and Dr Prathiba Shenoy for their help with interpretation!

Further Reading


Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.


ST Elevation in aVR