Very Subtle Inferior STE elevation seen only on 2nd ECG done 42 minutes later; Non STEMI with RCA occlusion
Posted Mar 29 2010 10:07am
I'm having difficulty with the blogger software. It won't let me place the ECG where I want it, so just know that the top ECG is "ECG #1" and the next is "ECG #2"
A 45 year old male presented after several hours of stuttering chest pain (a "big chest pressure right in the middle of my chest"), now with constant pain that started approximately 100 minutes prior to presentation. He has a history of GERD with "heartburn", no history of cardiac disease, but does have hypertension and hypercholesterolemia. He has a 21 year pack year smoking history but quit 5 years ago. He also has a h/o HIV/AIDS.
See ECG #1 on presentation
There is a significant Q wave in lead III, consistent with old inferior MI. There is a trace of ST elevation in inferior leads, but this was not different from a previous ECG. Appropriately, no action was taken.
The pain continued, and 42 minutes later ECG #2 was recorded:
There is now very subtle (less than 1 mm) ST elevation in leads III and aVF, with minimal reciprocal depression in aVL. This amount of ST elevation does not meet the definition of STEMI, but there is definite ACS with dynamic ST segments, and refractory chest pain. Thus it is appropriate to activate the cath lab.
There was a total occlusion of the RCA, thrombus was suctioned and the lesion was stented. The peak troponin was 38 ng/ml. The door to balloon time (DBT) is measured from the first diagnostic ECG, and so was 58 minutes. Technically, the record of this DBT need not be kept because without 1 mm of STE in 2 consecutive leads, this does not meet the definition of STEMI.
It is clear, however, that this definition is arbitrary: what is important is that there is an occluded artery and a significant amount of myocardium at imminent risk of infarction.