A reader texted this ECG without any clinical information, with the question:
“This is not a Subtle ECG, right?”
The reader reported that this ECG was not recognized as abnormal and that he himself had found it at the doctor’s station shortly after it was recorded.
The reader was concerned about the towering anterior T-waves and the small S-waves in V2 and V3.
The computer read it as benign early repolarization and the treating physician did not notice that it might be something else.
The reader activated the cath lab.
The reader asked another doc for whom he has great respect to look at it, and he also thought it was early repolarization.
It was a 40-something male with stuttering chest pain.
Outcome: proximal LAD occlusion.
The ST elevation does not meet STEMI criteria, as is very common in LAD occlusion.
However, to me and to my former resident, this is an obvious LAD occlusion because of the enormous T-waves, and the small QRS, with especially small S-waves, which almost meet the definition of terminal QRS distortion (but not quite).
I told him that V2 and V3 manifest a “forme fruste” of terminal QRS distortion, (“forme fruste:” an atypical or attenuated manifestation of a disease or syndrome).
This ECG is not obvious to everyone, as is clear from what happened in this ED.
And that is why I developed the formulas for differentiating the two entities.
How would the formulas fare?
I do not have the computerized QTc, but I measure the QT at 400 and the RR interval at 760. So the QTc is 470.
STE60V3 = 2.5 mm
RAV4 = 9.5 mm
QRSV2 = 5 mm
3-variable formula: 30.7 (far greater than 23.4, the most accurate cutpoint)
4-variable formula: 23.8 (far greater than 18.2, the most accurate cutpoint)
Even if the QTc was only 400 ms, the values would still be positive:
Both of these values are extremely high and diagnostic of LAD occlusion.
1. Use the formulas when there is ST elevation that you think is due to early repolarization.
2. Be suspicious of coronary occlusion when the T-wave towers over the R-wave, especially if in more than consecutive lead.
3. Do not believe the computer when it says normal or early repolarization. Interpret it yourself.
4. Use the formulas when there is any question.
See many cases of occlusion in which the computer interpretation was totally normal: