Friday, 16 October 2015

ECG of the Week - 12th October 2015 - Interpretation

The following ECG's are from a 17 yr old male who presented with palpitations for the last hour. He is normal fit and well. He denies taking any medications or drugs.
I don't know the exact time frames between these ECG's and what treatment, if any, was instituted between them.

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Key points:

  • Narrow complex tachycardia rate ~162 bpm
  • Atrial activity visible in V1 with upright narrow wave which are inverted in the inferior leads
  • Irregularity noted in initial portion of the ECG and within leads aVR, aVL, aVF


  • Atrial flutter
  • Atrial tachycardia 

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Key points:

  • Initial 10 complexes irregular without organised atrial activity
  • Followed by single sinus complex then 2 ventricular complexes
  • Period of flutter / atrial tachycardia
  • Pause ~1.2 seconds followed by sinus complex
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Key points:

  • Initial 5 complexes sinus - note p wave morphology is distinctly different than that seen in the first 2 ECG's
  • Premature atrial complex then initiates the onset of a narrow complex tachycardia with a brief 'wind-up' period of rate increase

Click to enlarge 
Key points:

  • Regular narrow complex tachycardia ~140 bpm
  • Inverted atrial activity in inferior leads with small upright atrial activity in lead V1
  • Inferior 'saw-tooth' pattern looks most like atrial flutter
Click to enlarge
Key points:

  • Finally back in sinus !
  • Otherwise largely unremarkable ECG

References / Further Reading

Life in the Fast Lane

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