Friday, 17 October 2014

ECG of the Week - 13th October 2014 - Interpretation

This ECG is from a 45 yr old female. She presented with abdominal pain and vomiting. Investigations revealed an acute small bowel obstruction. Prior to admission to the ward a 'routine' ECG was performed and is below.
Check out the comments from our original post here.

Click to enlarge

Rate:
  • Mean ventricular rate ~78 bpm
Rhythm:
  • Regularly irregular
  • Repeating pattern of sinus complex followed by two ventricular complexes

Axis:
  • Sinus complexes: Normal
  • Ventricular complexes: Left axis deviation
Intervals - Sinus Complexes:
  • PR - Normal (140ms)
  • QRS - Normal (80ms)
  • QT - 380ms
Intervals - Ventricular Complexes:
  • QRS - Prolonged (120-140ms)
  • QT - 360 ms
Segments:

  • Minor ST elevation sinus complex in lead V6
  • Ventricular complexes show appropriate ST segment and T wave discordant change

Additional:

  • Notching in terminal portion of ventricular QRS best seen in leads aVL and aVF ? native atrial activity - thanks to Ken for spotting this.

Interpretation:

Benign arrhythmia which will likely resolve once the underlying bowel obstruction has resolved. 
Causes could include:

  • Electrolyte abnormality
  • Acid/base disturbance
  • High vagal tone secondary to pain and nausea
  • Drug toxicity pending a review of the patient's usual medication



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.