## Saturday, September 30, 2017

### 30 yo woman with chest pain and a "normal ECG" by the computer, this one prehospital

This was sent by paramedics in the Northwest Ambulance Service in the UK.  James Alameddine credits his partner, Gary Wilson.

Case

A 30 year old woman complained of chest pain and called 911.

 As you can see, the computer interpretation is "normal"What do you think?

This very perceptive medic noticed that the T-wave in V4 is far too tall for the QRS.  Very abnormal.  But computers are not programmed to find all abnormalities, including many that are dangerous.  This is this one.

There is (as the computer measures -- at the side) more than 1 mm of STE in V2 and V3, but not the 1.5 mm that would trigger "STEMI" in a woman.

Thus, you have to decide if this STE is due to normal variant or due to ischemia.  Normal Variant ST Elevation always has good R-wave progression, and here the R-wave in V4 is only 3 mm.

If we use the 3-variable formula, with STE60V3 = 2 mm, QTc = 413, and RAV4 = 3, the value returns at 25.8 which is clearly diagnostic of LAD occlusion.

The 4-variable formula which includes the QRS amplitude in V2 turns out to be: 20.6 (most accurate cutoff is 18.2), so both formulas predict LAD occlusion.

The T-waves in V4-V6 should never be taller than the R-wave and should even be far less tall.

They should look like this:

Here are some more examples of hyperacute T-waves in V4-V6:

### Chest pain in a 42 yo, relieved by Maalox and viscous lidocaine

This one was also called "normal" by the computer (but in this case, also by the physician)

Case continued:

Because of this hyperacute T-wave, the medic continued to record serial ECGs over the next 20 minutes:
 Now there is subtle ST depression in lead III, seen by the computer

 Clear ST Elevation in I, aVL, V4-V6, with reciprocal ST depression in II, III, aVF

The medics activated the cath lab and the patient went straight to the cath lab and had an LAD occlusion opened and stented.

The medics were unable to get any other information such as troponins or echo.

Here are more cases of "normal" ECGs, posted on September 28:

### Just a few cases that the computer called "normal"

Question: How would you like it if there was a policy that patients with "normal" ECGs do not need it to be reviewed by the physician?

This young woman with chest pain would be listed as "very low risk" and would sit in triage for many hours until she arrests or loses half of her myocardium.

1. Great ECG. Hope to see a validation from Smith+V2 rule! A question frequently asked by EP working far away from cath labs: would you lyse such patient? No data about this, so I answer "no". Is there any place to think about lysing those patients in some situation? Cheers.

1. Alain, I also answer No!, and many say that they could never get their interventionalist to act on such a case. I answer that the reponse to such an ECG is not to activate the cath lab, but to do intensive evaluation: serial ECGs and contrast Echo. Some may turn out to be false positives. I give a talk on "The False STEMI-non-STEMI Dichotomy." The other false dichotomy is 1) Activate cath lab or 2) don't activate (also: 1) give lytics or 2) don't give lytics. There is a middle ground: evaluate intensively. don't simply "rule out MI" with biomarkers: they will only turn positive when too late.
Thanks for the great comment!
I'm sitting next to Pierre now. He will go back to Paris today.
Steve

2. The T wave in Lead 3 is also quite tall (hyperacute).. Any comments on that?
Thank you...

1. MG,
I agree but that is very subtle and I'm not certain how specific it would be.
Steve