A 30-something with acute chest pain

This was sent to me from Sam Ghali (@EM_Resus) with no other information.  I assumed it was a patient with acute chest pain.

"What do you think, Steve?  Real or just fake?"

What do YOU think?

It has some inferior ST elevation with some reciprocal ST depression and inverted T in aVL.  This usually indicates inferior OMI.

My answer: "Fake: pretty certain, but not 100% certain."

Sam: "why do you say fake?"

Smith: "Gestalt, but if I must explain: well formed J-waves and high voltage R waves."

Sam: "Yeah I think too the negative QRS in aVL takes away from changes that may be interpreted as “reciprocal”"

Smith: "did the cath lab get activated?"

Sam: "Yes, this case was sent to me.  It was a man in his 30s with chest pain.  Coronaries were clean.  Troponins were all negative -- the patient ruled out for acute MI."

Finally, Sam: "Honestly in addition to expert ECG interpretation I think skilled bedside echo can prevent a lot of these activations."

I agree, however: 

1) I don't think you can get a good enough echo without bubble contrast.  

2) You need to be just as expert at echo as I am at the ECG.

3) Echo is another step that takes time.  Time is myocardium.

So the best course of action:

 Use the PMCardio Queen of Hearts AI in ECG interpretation.

Not OMI with High Confidence

Click here to sign up for Queen of Hearts Access

We showed that the Queen of Hearts decreases false positive cath lab activations:

1) Published recently in Prehospital Emergency Care

Baker PO et al. Artificial Intelligence Driven Prehospital ECG Interpretation for the Reduction of False Positive Emergent Cardiac Catheterization Lab Activations: A Retrospective Cohort Study

This showed a decrease of false positive cath lab activations from 69 by medics to 29 by use of the Queen of Hearts, while still identifying all 48 true positive OMI.   I had only 9 false positives but I missed 2 OMI.  The integrated device algorithm had 42 false positives and one missed OMI.

Full text!

2) To be presented at AHA conference in Chicago in 2 weeks: 

Sharkey SW et al.  Performance of Artificial Intelligence Powered ECG Analysis in Suspected ST-Segment Elevation Myocardial Infarction.  This showed a decrease in false positive cath lab activations from 637 out of 2526 (25%) to 403 our of 2526 (16%), a 37% decrease in false positive activations.  Of those with MI and a culprit, 4% were missed (called "Not OMI"), but these were not necessarily occlusions (most MI with an open artery have a culprit), and many were LBBB.

Click here to sign up for Queen of Hearts Access

===================================

MY Comment, by KEN GRAUER, MD (10/3/2024):  

===================================

I looked at the ECG in today’s case knowing only that the patient was a younger male adult with CP (Chest Pain).

• While statistical likelihood of acute OMI is clearly lower in younger adults — nothing is ruled out by age alone (as per My Comment in the January 9, 2023 and December 5, 2023 posts in Dr. Smith's ECG Blog).
• Without knowing more about today’s case — I also thought (as did Dr. Smith) — that this ECG (that I’ve labeled in Figure-1) was likely to be a “fake”. 

ECG Features suggesting "Fake"

As per Dr. Sam Ghali (who sent us today's case) — serial Troponins were clearly indicated since the patient presented to the ED. These were all negative. I'd defer on the question of whether cardiac catheterization was needed by saying, "Ya gotta be there" — but there clearly are ECG features suggesting no OMI.

• The rhythm for the ECG in Figure-1 is sinus — with normal intervals and axis (mean QRS axis about +80 degrees). There is no chamber enlargement.
• One wonders about lead placement, given abrupt transition from the similar-looking predominantly negative QRS complexes in leads V1,V2 — to a nearly all-positive QRS by lead V3.

Regarding ST-T Waves:

• There clearly is ST elevation in each of the inferior leads. 
• I suspect the presence of T wave inversion in lead aVL increased concern about reciprocal ST-T wave changes — which must have been perceived as suggestive of acute inferior OMI, since cardiac catheterization was performed.

There is No Reciprocal ST-T Depression:
We have often referred to the almost "magical" mirror-image relationship for ST-T waves in leads III and aVL when there is acute inferior MI (See My Comment in the September 30, 2019 post in Dr. Smith's ECG Blog, as well as many others). That said — I would not interpret ST-T wave appearance in lead aVL of today's ECG as a "reciprocal" change.

• The T wave vector often follows closely behind the QRS vector. As a result — when the QRS is predominantly negative in lead aVL — then the T wave in this lead may also be negative as a normal finding. This is precisely what we see in ECG #1 — in which the frontal plane axis is +80 degrees (which is most probably the reason for the shallow T wave inversion highlighted by the BLUE arrow in this lead).
• Contrast this normal amount of T wave inversion seen within the BLUE rectangle in ECG #1 — with the disproportionately "bulky" T wave inversion seen within the RED insert of lead aVL that I've excerpted from the initial ECG of a different patient who was having an acute OMI (See My Comment in the September 27, 2024 post).
• Therefore — there is no reciprocal ST-T wave depression in today's case!

There is No Sign of Posterior OMI:
It is common to see indication of posterior OMI when (if) there is inferior OMI. Posterior OMI is typically diagnosed by the finding of chest lead ST depression that is maximal in leads V2, V3 and/or V4. We do not see this in ECG #1.

• As noted above — the similar-appearing QRST complex in leads V1,V2 — followed by abrupt transition to a predominantly positive QRS by lead V3 — suggests there may be an error with precordial electrode lead placement.
• That said — None of the chest leads show ST depression.
• While the absence of indication of posterior OMI does not rule out the possibility of acute inferior OMI — it does make this less likely.

There ARE Signs of a Repolarization Variant:

Among the many posts in which we've reviewed cases of repolarization variants — is the May 23, 2022 post. From this post:

• Among the most suggestive ECG features of a repolarization variant — is the presence of an end-QRS notch (J wave) — and/or — a "slur" on the downslope of a prominent R wave.
• Although subtle — J-point notching is seen in leads V4 and V5 of ECG #1 (within the dotted PURPLE circles in these leads).
• A "slur" is seen on the downslope of the R waves in leads II,III,aVF and V6 (GREEN arrows in these leads).
• 
  
• Finally — Not only are reciprocal changes absent in ECG #1 — but a similar shape to the ST segments is seen in multiple leads (ie, leads I,II,III; aVF; V3,4,5,6) — which is more characteristic of a repolarization variant (as opposed to the ST-T wave changes of acute OMI that more often localize).

BOTTOM Line in Today's CASE: While fully acknowledging that in a patient who presents to the ED with CP — "Ya gotta be there" to best determine how much evaluation is needed to rule an OMI in or out. That said — I thought the ECG in Figure-1 looked more like a "fake" than like an acute OMI.

• Negative serial Troponins were needed to rule out an acute event.
• Serial ECGs would be expected to show no evolution.
• A normal Echo obtained during CP would support this being a repolarization variant.
• If a final test was perceived as "needed" — perhaps a normal coronary CT angiogram could have helped to avoid cardiac catheterization.

Figure-1: I’ve labeled the initial ECG in today's case. The RED Insert for lead aVL is excerpted from My Comment in the September 27, 2024 post in Dr. Smith's ECG Blog (taken from the initial ECG in that Sept. 27 post).