Wednesday, 13 March 2013

ECG of the Week - 11th March 2013 - Interpretation

This week's ECG is from a 57 year old female.
 
I don't have any presenting complaints for this case but it is likely she would complain of weakness.
 
 
Click to enlarge
Rate:
  • 60 bpm
Rhythm:
  • Sinus Arrhythmia
 
Axis:
  • Normal (50 deg)
Intervals:
  • PR - Prolonged (~220ms)
  • QRS - Normal (100ms in lead II, prolonged in lead V2)
  • Apparent QT - 680ms (QTc Bazette ~ 710 ms)
Segments:
  • ST Depression Leads I, II, V2-6
  • ST Elevation aVR
Additional:
  • Ventricular Ectopic
  • Prominent U waves
  • T-U Fusion
    • Best visualised in leads II, III, aVF, V2-6
    • Initial T wave is inverted and merges with large U wave
    • Results in apparent QT prolongation due to fusion
    • Best considered QU prolongation
Interpretation:
 
  • Multiple ECG features consistent with hypokalaemia +/- hypomagnesaemia
 
This patient had a K+ of 1.6 mmol/L confirmed by a VBG, result below.
 
 
 
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.