ECG #20

A 30-year-old woman presents to ED with pre-syncopal symptoms. Describe and interpret her 12-lead electrocardiogram:

 

Repeat ECG with left-sided precordial electrode placement:

 

These ECG changes are similar to the characteristic pattern seen in dextrocardia:

Dextrocardia
(Image courtesy of LITFL: https://lifeinthefastlane.com/ecg-library/basics/dextrocardia/)

  • Right axis deviation
  • Inversion of aVR (global positivity)
  • Inversion of lead I (global negativity)
  • Absent R-wave progression in the precordial leads with dominant S waves throughout

Of note, reversal of the left and right upper limb electrodes may produce a similar picture to dextrocardia in the limb leads, but with normal appearances in the precordial leads.

See this post from LITFL for an excellent review on on the topic of limb lead reversals.