A 70 y.o. woman who presented with L arm pain that started at 6:45 in the morning when she woke up. Pain was also in the upper back with some discomfort in the L chest. Described as “Achy” pain. She initially thought she must have slept wrong.  No associated SOB, diaphoresis, or dizziness. No similar pain previously.  No h/o CAD. She sat and rested but the pain got stronger, so she took 2 ASA. She felt a little “clammy.”  The pain went away after ~15 min. She lay down for ~20-25 min and while lying down the pain returned and persisted x 10 min prior to resolving again.  She called 911. 

She was pain free when the medics recorded 3 ECGs over 40 minutes.  They all were similar to the first:

V6 is missing.  There are Q-waves in leads V3 and V4, with ST elevation and a large T-wave.  Normally, one might think this ST elevation and T-wave is early repolarization, but early repol like this should 1) not occur in a 70 yo woman 2) never have Q-waves.  Therefore, this is old MI with acute ischemia or acute STEMI.

In the ED she was pain free.  This was her ECG at presentation:

QTc 442 ms.  The T-waves in V3 and V4 are still large, but definitely smaller than in the prehospital ECGs.  This is typical of hyperacute T-waves during reperfusion.  You can compare the T-waves with her baseline (next ECG below).  Additionally, there are new Q-waves in V2 and V3.

look here for more on hyperacute T-waves:

https://drsmithsecgblog.com/search/label/hyperacute%20T-waves

These ECG indicate that, at the time the patient was having pain, her LAD was occluded or nearly occluded.  Old ECG from 3 years prior:

QTc 405 ms.  Normal previous ECG.  No Q-waves.  No ST elevation. No large T-waves.

So the patient has a spontaneously reperfused LAD.  Antiplatelet and antithrombotic therapy was begun.

At 113 minutes after presentation (first troponin was less than 0.04):

QTc 447 ms.  T-waves continue to diminish.  Q-wave in V2, V3.

Just before cath, time = 240 minutes:

QTc 447 ms.  T-waves very diminished now

Here is a composite of V4-V6 from previous to prehospital to ED:

2 hours after LAD intervention (80% stenosis with hazy LAD thrombus):

QTc 450.  T-waves begin to invert.  If this was the first ECG you had recorded in the ED, it would be Wellens’ syndrome.

Next Day.  Troponin I peaked at 2.28 mcg/L.  The septum, anterior wall, and apex are akinetic on echo (myocardial stunning):

T-waves evolve to become deeper and more symmetric

3rd day, 48 hours.

T-wave evolution continues

6th day, 120 hours:  Normal echocardiogram now:

T-wave evolution continues

7 weeks later:  

R-waves present, T-wave inversion gone

3 months later:

Complete recovery of ECG

Summary:

1) With a large amount of myocardium at risk, there is a large wall motion abnormality

2) Hyperacute T-waves are a sign of a large amount of myocardium at risk and that it is still viable

3) With minimal actual myocardial cell death (infarction), as shown by a low peak troponin, the myocardium will recover:

a) The myocardial function (as shown by echo) will recover (this may take weeks)

b) The ECG will recover (this may take months, as in this case).