de Winter's T-waves evolve into Wellens' waves

This comes from a paramedic in Hungary named Farkas László:

This patient had chest pain that then resolved:

There is diffuse ST depression, with ST Elevation in aVR and a hyperacute T-wave in lead V3
V3 is likely a de Winter's T-wave (ST depression with large upright T-wave)

Since this T-wave is not obviously massive, one might think this is a posterior MI (right precordial ST depression) or simply diffuse subendocardial ischemia (diffuse ST depression with STE in aVR).

11 minutes later, the chest pain was gone, suggesting spontaneous reperfusion (autolysis of thrombus).  

This ECG was recorded:

All ST depression in V3 is gone
Only residual ST depression remains
The T-waves in V2 and V3 are smaller
This rules out posterior MI: as an artery reperfuses in posterior MI, the T-wave gets larger!
(Posterior reperfusion T-waves)

See posterior reperfusion T-waves: 

2 Examples of Posterior Reperfusion T-waves

Here is our research on this topic: http://emj.bmj.com/content/34/2/119
8 minutes later:

All precordial T-waves are smaller still

7 minutes later:

There is less ST depression

Another 16 minutes later:

There is new ST elevation, but, in addition, Wellens' waves are emerging (Wellens' pattern A, terminal T-wave inversion in V2-V4, and a little in V5)

This is still more evidence that the LAD is the infarct-related vessel.


Another 7 minutes later

ST Elevation is resolving, terminal T-wave inversion remains

Here is a .gif of lead V4 from T = 0-11-19-26-42-49 minutes:

The cath lab was activated and a 90% thrombotic subtotal occlusion with flow was found.

I think that de Winter's T-waves really represent very tight subtotal occlusion of the LAD.  Complete occlusion results in ST Elevation.  Very tight stenosis results in subendocardial ischemia with diffuse ST depression and STE in aVR.  de Winter's is a point halfway between these two: a hybrid of STEMI and diffuse ST depression with STE in aVR.

Here is another example of this:

Is the LAD really completely occluded when there are de Winter's waves?

Of course, when the LAD reperfuses, we usually get Wellens' waves (reperfusion T-waves).  So even though the ECG never manifested outright STEMI, the small amount of infarct that resulted from this subtotal occlusion resulted in the same T-wave evolution that we would have seen with outright STEMI.