When I was in medical school or even in my residency, my thought was like – oh, you can’t miss a STEMI, it is just too obvious to be missed. But the truth is that it is very possible to miss a STEMI and actually in real life, many STEMIs have been missed. The reasons why STEMIs are missed:
STEMI EKG changes can be transient. Once I thought after STEMI the EKG should go down the route of showing q waves etc, but sometimes STEMI EKG can go back to normal looking. So if somehow the STEMI EKG is not cited or not seen or misplaced (oh those paper EKGs flying everywhere…), the diagnosis is missed. I remember where I was trained, ER attending always have to sign the EKG with date/time and their name, a really good practice indeed to make sure every EKG is read by an attending. While on the floor, we don’t have this kind of practice or habit, so I did encounter a case that the EKG done during a rapid response was later found to have clear patterns of STEMI.
Secondly, as you all know there are STEMI equivalents and posterior MI. Sometimes V2-V3 elevation could mimic early repolarization pattern. Single avR elevation. With some residency program hosted by a hospital without a cardiac cath lab, most of these patients are screened and shipped to somewhere else, and residents are not exposed to as much high-risk EKGs as they should.