"Lead Malposition vs Dextrocardia"

26 years old female, normally well, not on any medications except contraceptive pills, presented to ED with 1 day history of left sided chest pain, dull, more with inspiration, not related to any specific movements or position, with no associated symptoms & with normal vital signs.

What do you think about her ECG?

Discussion:

The first thing to notice in this ECG is that the P waves, the complexes & T waves are NEGATIVE in some of the limb leads other than aVR (I & aVL), & the P wave is POSITIVE in aVR.

The differential diagnosis for this is either Dextrocardia or Limb Lead Malposition (The ECG below shows limb lead malposition)

But in lead malposition, you get a completely normal chest leads (because the malposition is in the limb leads).

If we go back to our case, you will notice that the R wave started tall in V1 & got shorter & shorter towards V6 which is opposite what is normal (Reversed R wave progression).

You will also notice that there is a T wave inversion in the chest leads.

Lastly, the size of the complexes gets smaller the more you move from V1 to V6 (as if you are going away from the heart).

If you combine all of the above (limb lead malposition pattern + Reversed R wave progression in chest leads + T wave inversion in the chest leads + smaller complexes going from V1 to V6), you will get the answer.

Answer:

This was a case of "Dextrocardia, associated with situs inversus totalis" with the gastric gas in the right side & the liver in the left.

This is her CXR

Here is the right sided leads ECG of the same patient to check for ischemia. You will notice that everything was corrected in the chest leads

She had a low risk score for Pulmonary Embolism with negative D-dimer, so she was sent home as a non-specific chest pain likely costochondritis case.

Here is a link to a video that discusses the above case:

https://www.youtube.com/watch?v=RrNhJySxs_c&list=PL9UPY1P9K6fNSHzP_gPIbTu6TjZGAL0iR

Thanks, I hope you find this useful.