Sunday, April 17, 2011

What are these large precordial T-waves?

This patient suffered from chest pain and is now pain free:

There is sinus rhythm at a rate of 75.  There is a nonspecific intraventricular conduction delay (QRS duration 120 ms). There are massive precordial T-waves suggesting anterior STEMI.  However, the astute observer will notice the inferior (and lateral) T-wave inversions as well.  So there is a reperfused infero-lateral MI.  Does the patient also now have an acute anterior STEMI? 
















The answer is no.  These are enlarged T-waves due to reperfusion of the posterior wall, recorded from the anterior chest leads.   This could be strongly suspected based on: 1) resolution of chest pain and 2) inferior T-wave inversion, suggesting a reperfused inferior MI (which correlates with a reperfused posterior MI because inferior and posterior MI are frequently concomitant.

Notice there is also early transition of the R-waves.  These are analogous to posterior Q-waves.  The loss of posteriorly directed forces means there is less vector to counteract the anterior wall voltage, so there is more anterior wall voltage visible.

If there were posterior leads, you would see loss of R-wave amplitude (or a Q-wave) and deep T-wave inversion.

Let's go back in time:


This 39 year old had onset of chest pain at work.  After 15 minutes, he called 911.  The medics recorded this ECG:

Obvious infero-postero-lateral STEMI

He arrived at the ED 40 minutes after onset of pain and went directly to the cath lab, where a 100% occluded circumflex was opened, with a door to balloon time of 24 minutes (64 minute symptom onset to balloon time).

Here is the first post cath ECG, 174 minutes after arrival:

There are now inferior reperfusion T-waves in II, III, and aVF.  But now also "hyperacute" T-waves anterior.
The infero-posterior STEMI has resolved with PCI.  But what are these large anterior T-waves?

Is there now an anterior STEMI?

No.

These are something that has never been described in the literature, and I call them "posterior reperfusion T-waves."  I have seen these many times, and have other posts of this phenomenon:
http://hqmeded-ecg.blogspot.com/search/label/posterior%20reperfusion%20T-waves
We are now in the process of formally studying this in order to describe it in a paper.

Explanation: These are Wellens' T-waves as recorded from the opposite side of the chest.  If you can imagine Wellens' anterior inverted T-waves recorded on the posterior wall, that great negativity (recorded anterior) would be positive (recorded posterior).  Conversely, if the reperfusion T-wave would show an inverted T-wave of the posterior wall if recorded posteriorly, then it would have enhanced positive amplitude if recorded on anterior precordial leads, as here.

As with Wellens' T-waves, they evolve and become more striking.  Here is one at 408 minutes after arrival:

Precordial T-waves are even more strikingly hyperacute.  These are developing posterior reperfusion T-waves. There is now also the beginning of T-wave inversion in V6.

36 hours later, they persist:

Notice also how the inferior and lateral reperfusion T-waves are evolving to become deeper and more symmetric

An echocardiogram showed postero-inferolateral wall motion abnormality. The troponin I peaked at 102 ng/ml.

3 comments:

  1. Great ECGs-- it looks similar to the "type 3" Wellens' pattern: http://www.ncbi.nlm.nih.gov/pubmed?term=18987380

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  2. Exactly, but it is the opposite! (open artery, not closed. Posterior, not anterior)

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  3. Very Nice ! This is the same ECG findings you can see in the first 3 minutes after exercise stress testing in healthy athletes (tall T waves on precordial leads)

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