Wednesday, 23 August 2017

ECG of the Week - 21st August 2017 - Interpretation

This ECG is from a 35 yr old male Type 1 diabetic. He presents feeling generally unwell with abdominal pain and dysponea.






Click to enlarge
Rate:
  • 48 bpm
Rhythm:
  • Irregular
  • Nil P waves visible
Axis:
  • Right axis deviation
Intervals:
  • QRS - Prolonged
Additional:
  • ST Elevation leads I, aVL, V1-4
  • ST depression leads III, aVF
  • Bizarre broad QRS without typical BBB
  • Prominent T waves leads V3-6
Key abnormalities:

  • Slow atrial fibrillation
  • QRS Prolongation
  • High lateral ST elevation
  • Prominent precordial T waves

The differentials of these ECG findings are relatively broad but the immediate life-threats would be:

  • Acute myocardial infarction
  • Hyperkalaemia +/- acidaemia
  • Drug toxicity

Other causes include myocarditis, cardiomyopathy and hypothermia.

We must always take our ECG differentials to the bedside and consider them within the clinical presentation and scenario. ECG abnormalities in the acutely unwell diabetic should always prompt consideration of hyperkalaemia and acid-base disturbance as the primary cause. We must also be mindful that diabetic emergencies can be precipitated by acute cardiac ischaemia and also cause hypercoagulable states.

This patient had no associated chest pain nor any history of cardiac disease. The patients initial VBG showed diabetic ketoacidosis with severe hyperkalaemia, K 8.7 mmol/L. Following initial treatment of DKA and hyperkalaemia a repeat ECG was performed with K 5.4 mmol/L.


Click to enlarge
We can now see resolution of the QRS prolongation, restoration of sinus rhythm and normalisation of the ST / T wave changes.
References / Further Reading

Life in the Fast Lane

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