New upright T-wave that is NOT pseudonormalization
Posted Aug 02 2010 7:11am
A 79 yo female presented with crescendo angina. She has a history of anterior STEMI a few years ago treated with tPA. She has DM, HTN, and smokes. She was pain free at the time of this ECG (ECG #1)
There is one mm of ST elevation in each of V1-V3, along with deep QS-waves and upright but not large or tall T-waves. This is typical "LV aneurysm" morphology (otherwise known as persistent ST elevation after old MI). This typically has a low T/QRS ratio..
It is always wise to compare with a previous ECG, but only with knowledge of the normal evolution of post-MI ECGs. Here are the previous ECGs ECG #2 is the last ECG, recorded after resolution of the previous anterior STEMI. The T-waves are inverted and QS-waves are present. This is a typical ECG of post transmural MI, with shallow T-wave inversion (Non-STEMIs have deeper T-wave inversion and preservation of some R-wave, often a QR-wave).
ECG #3 is the one obviously diagnostic of anterior STEMI
Why are the T-waves upright now? Is it pseudonormalization? No. In the normal evolution (over months) of the post-MI ECG, T inversion (usually) becomes upright. On the other hand, pseudonormalization happens acutely (within the first week or two), usually after a reperfused MI and is due to re-occlusion. The T-waves are large and hyperacute.
So ECG #1 is not due to pseudonormalization. If the patient has ongoing symptoms (unlike this one), serial ECGs are indicated because hyperacute T-waves and ST elevation may develop, but this ECG#1 represents the expected ECG evolution of this patient with previous transmural MI. This patient ruled out for MI by troponin.
For an example of true pseudonormalization, see the case posted on January 12, 2010.