This 18 year old presented with syncope and tachycardia.

Similar to the last case (the “quiz”), there is sinus tachycardia with precordial T-wave inversion with TW inversion in lead III also.  The morphology of these T inversions is highly suggestive, but unlike the previous case, not diagnostic.  There is also, arguably, S1Q3T3 depending on whether one considers the S-wave to be “prominent.”  There is no right axis deviation, but there is a S-wave.  (Does anyone know of a definition of “prominent” S-wave in S1Q3T3?)

Immediately, a bedside echo was done.  Here is the video:

This shows a huge and poorly functional RV.

Here is a still picture from the video:

The RV is on the left, the LV on the right (thick-walled).  The RV is very enlarged and looks like a “D”.  Accordingly, this is called the “D” sign.

  This is diagnostic for pulmonary embolism, which was subsequently proven. Thrombolytic therapy might have been given, but at least partly because of head trauma from syncope, it was not.