CCU so they're already on tele, take a look at the screen and determine the basics: rate, rhythm, ST changes. If it's rhythm then electricity is the answer if it's shockable. Quick history is important, ie, did they just pull the femoral sheath out and the patient vagaled down to near death. This caused me a few moments of terror my intern year. Atropine is then the fix, glyco if it wasn't as urgent or bad, but this sounds ugly by the description. Look at the patient, probably non-responsive but intubated or not is important. If the patient looks clinically way too good to have a pressure of 60/30 then press the button and cycle another pressure. If they are vented are the peak pressure alarms sounding, etc. All of this should take about 3 seconds as you enter the room.
What's going through your head now is, shock. Septic, not likely. Spinal, no trauma. Hypovolemia, sure if when they pulled the sheath out the patient bled 2 liters which you should notice on your quick survey of the room. Also with the pulmonary edema slamming in fluid is not something that is fun without a swan. That pretty much leaves cardiogenic. But how could they re-infarct on the heparin drip, plavix, aspirin, etc? Could be a coronary dissection during the PTCI. Also could be a coronary steal if they stented across a good vessel and occluded flow. What about wall rupture and the subsequent tamponade?
In the meantime this is a code situation. If ACLS protocols are applicable, then follow them. If not call for some epi if you have no swan, and I'm assuming you don't. Call the code, call your resident, call the family.