Wednesday, 16 March 2016

ECG of the Week - 14th March 2016 - Interpretation

The following ECG is from a 34 yr old female who presented to the Emergency Department complaining of progressive weakness. She has known Gitelman syndrome and recently had several medications changed.




Click to enlarge

Rate:
  • 78 bpm
Rhythm:
  • Regular
  • Sinus rhythm

Axis:
  • RAD (-33 deg)
Intervals:
  • PR - Normal (~170ms)
  • QRS - Normal (80ms)
  • Apparent QT - 560ms (QTc Bazette 640 ms)
    • Due to T-U fusion
    • See labelled image below
Additional:

  • Massive U waves
    • Mimic T waves - see labelled image below
    • Nearly merging into subsequent P waves
  • T wave inversion leads V1-2

T & U Waves Labelled in leads V2-3
Click to enlarge


Interpretation:

  • ECG features consistent with hypokalaemia


What happened ?

The patient had urgent electrolytes which showed:

  • K              1.7                [3.4 - 5.5 mmol/L ]
  • Cor Cal     2.45             [2.20 - 2.55 mmol/L]
  • Mg            0.73             [0.70 - 1.20 mmol/L]

She was admitted to the HDU and a PICC line inserted due to high K replacement requirements.
The patient made an uneventful recovery and was discharges once her potassium reached a consistently safe level.
For a bit more information check out:


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.