Wednesday, 12 September 2012

ECG of the Week - 10th September 2012 - Interpretation

This ECG is from an 84 year old male, no other clinical information available.





Click to enlarge

Rate:
  • ~ 48
Rhythm:
  • Sinus
  • Irregular
 Axis:
  • Extreme / NW (-141 deg)
Intervals:
  • PR - Prolonged (~240ms)
  • QRS - Normal (80ms)
  • QT - ~480ms (QTc Bazette ~ 400 ms - difficult due to variable rate & T flattening)
Additional:

  • T Wave Flattening V5-6, I, II, III, aVF
  • U Waves V2-6, ? I & II - Apparent T wave in Lead II likely U wave
  • Dominant R wave aVR
  • R wave progression V2 to V3 appears abnormal
  • Movement Artefact between 3rd & 4th Complexes

Interpretation:

  • 1st Degree AV Block
  • Bradycardia
  • U waves & T wave changes suggestive of hypokalaemia - unfortunately unable to correlate with clinical case
  • Extreme Axis & Dominant R wave aVR consistent with Right Arm / Left Arm Lead Reversal - resultant Lead I inversion and Leads II / III switch places
  • Unusual R wave progression V2 to V3 - ? lead placement, ? patient habitus, ? lead reversal (unlikely due to local cable set-up)


Another ECG was performed with the Right Arm and Left Arm lead positions corrected and is shown below. Note Left Axis Deviation with corrected lead placement



Click to enlarge



References / Further Reading

Life in the Fast Lane

  • Hypokalaemia here
  • 1st Degree AV Block here
  • Lead Reversal Overview here
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.