Then you will be one up on many of your CC colleagues in fellowship b.c that is all that is really necessary in CC practice. You have a sick patient and you don't feel like waiting for cardiology to give you a formal read and you don't want to send the pt to CT for PE protocol unless the patient absolutely requires it.
For example, here is a classic situation. Pt is transferred to unit secondary to respiratory distress, post op day #4 from ex lap for SBO. Pt is saturating at 90% on non-rebreather, tachycardic at 115, BP 95/56 (baseline 120/80). 5 lead EKG on monitor shows no specific evidence of ischemia. Option #1: send labs, get 12 lead, maybe consider bipap, order CT PE protocol, intubate and place on MV. Option #2: send labs, order 12 lead, obtain bedside TTE to look for tamponade, measure estimated PASP and look for RV strain, access LV for wall motion abnormality.
Bedside TTE shows you significant wall motion abnormality without significant RV strain and only mildly elevated PASP. 12 lead EKG shows no specific findings. Based on TTE you cancel CT scan, order 4 baby ASA, 5000u heparin and consult cardiology. Cardiology arrives and 5 lead on monitor is now showing new LBBB. Pt goes to cath lab and has 3v disease with significant left main disease and receives CABG and eventually goes home.
The above is an actual case from my fellowship in which TTE was huge in narrowing my differential allowing me to quickly treat the patient's underlying pathology.