Wednesday, 29 February 2012

ECG of the Week - 27th February 2012 - Interpretation

This weeks ECG was from a 71yr old female.




Click to enlarge
Rate:
  • 72
Rhythm:
  • Regular
  • Sinus Rhythm
Axis:
  • Borderline LAD (-33 deg)
Intervals:
  • PR - Normal (~200ms)
  • QRS - Normal (100ms)
  • QT - 400ms (QTc Bazette ~ 430 ms)
Segments:
  • Minor Intraventricular conduction delay
Additional:
  • Low voltage
  • T inversion V1-3
  • U waves V3-5
  • Poor R wave progression
                               
Interpretation:
  • Low voltage ECG
  • Non-specific T wave changes
  • Borderline LAD

Low QRS Voltage ECG Definition
  • QRS Voltage less than 0.5mV (5mm) in all limb leads
  • QRS Voltage less than 1mV (10mm) in all precordial leads

Causes of low voltage ECG include:

  • ECG Calibration Error
  • Body habitus e.g. obesity
  • Pericardial Effusion
  • Pleural Effusion
  • Fluid Retention e.g. anasarca, cardiac failure, nephrotic syndrome, myxodema
  • Infiltrative Cardiomyopathy
  • COAD (hyperinflated lungs)
  • Pneumothorax

References / Further Reading

Life in the Fast Lane
  • Low QRS Voltage here
Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.