Written by Pendell Meyers, sent by anonymous, with additions by Smith
A man in his 40s had acute chest pain and called EMS.
EMS arrived and recorded this ECG:
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| What do you think? |
Here is the PMcardio Queen of Hearts interpretation of the ECG:
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| STEMI equivalent detected. Inferior and posterior OMI without STEMI criteria. |
See this article, in which using the Queen would decrease false positives substantially:
There is much more data that shows that the Queen of Hearts is both more sensitive AND more specific (see 3 studies at the bottom)
Case Continued
The ED physician reviewed the prehospital ECG as "No STEMI” at triage and did not order a repeat.
The patient was placed in the waiting room.
About an hour later another ECG was obtained:
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| Barely meets STEMI criteria in inferior leads, but obvious inferior and posterior OMI. Even lateral leads V5-V6 have HATW. |
The cath lab was now activated for STEMI.
Cath done around 4 hours after first medical contact (symptom onset time uncertain) revealed an RCA occlusion requiring thrombectomy and PCI.
Smith: How much does such a delay matter? See this graphic here from JAMA 2005, by legendary authors Gregg Stone and Harvey White. You can read the abstract (or of course the entire article) at the link provided. Very interesting.
SUMMARY: From onset of symptoms, a 2 hours delay, from hour 2 to hour 4, results in loss of 60% of the mortality benefit of reperfusion
Gersh BJ, Stone GW, White HD, Holmes DR Jr. Pharmacological facilitation of primary percutaneous coronary intervention for acute myocardial infarction: is the slope of the curve the shape of the future? JAMA [Internet] 2005;293(8):979–86. Available from: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15728169
The "STEMI metrics" for this patient reflect a "successful" time to cath within 90 minutes of the STEMI+ ECG. So the final diagnosis is STEMI, and there is no question or feedback about whether the acute coronary occlusion could have been identified sooner.
If I were the patient, I would want intervention to be 2 hours earlier, wouldn't you?
What would you want? Does the disease only matter when it becomes easy enough to see on the ECG without any dedicated training? Is the disease the ST segment? or is the disease acute coronary occlusion?
In our study below, among patients who actually had STEMI at some point on the ECG, the PMCardio Queen of Hearts AI Model was able to detect OMI a median of 3 hours earlier than STEMI criteria.
(And, in addition, she was able to detect many OMI that were never STEMI)
Herman, Meyers, Smith, et al. International Evaluation of an Artificial Intelligence-Powered Electrocardiogram Model Detecting Acute Coronary Occlusion Myocardial Infarction. EHJ DH. 2023.
More on Specificity of the Queen of Hearts:
1)
Perfect sensitivity and you can see the false positives at the bottom of the slide
2)
Look at the false positives on the right:
For the cardiologist, none of the FP had a culprit.
For the Queen, all 4 FPs had a culprit but the troponin was not high enough to qualify for this very strict OMI outcome definition requiring a peak hs troponin I of at least 5000 ng/L.
3)
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MY Comment, by KEN GRAUER, MD (3/23/2025):
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Although details from today’s case are limited — the “answer” should be obvious within seconds on seeing today’s initial ECG (TOP tracing that I have reproduced and labeled in Figure-1). This man in his 40s with acute CP (Chest Pain), severe enough to prompt him to call EMS — has had an infero-postero OMI that has-to-be assumed acute until proven otherwise.
- Learning more precisely when this patient’s CP began — and how severe his CP was at the time ECG #1 was obtained (as well as learning if this patient has a previous history of heart disease and what his “baseline” ECG looks like) — would help us to better determine the likely onset of his OMI.
- That said — there are a number of findings in this patient’s initial ECG that look recent, if not acute.
Why this Patient should NOT be sent to the Waiting Room:
After hearing the history and seeing the initial ECG in Figure-1 — today’s patient was sent to the Waiting Room. We are lucky this patient did not have a cardiac arrest while in the Waiting Room. Instead (as per Dr. Meyers) — worrisome ECG findings were evident on the initial ECG.
- My “eye” was immediately drawn to leads V2 and V3 (within the RED rectangle in ECG #1). In a patient with new CP — early transition (with a predominant R wave already in lead V2) — in association with loss of the normal slight, gently upsloping ST segment in leads V2,V3 (replaced by ST segment flattening — as highlighted by the RED arrows) is diagnostic of acute posterior OMI.
- Infarction Q waves are seen in each of the inferior leads (most notably in lead III). Considering the modest inferior lead QRS amplitudes — acuity is suggested by disproportionately "bulky" T waves in leads II and aVF (BLUE arrows in these leads). Even without reciprocal ST depression in lead aVL — in this patient with new CP, these findings are diagnostic of acute inferior OMI.
- KEY Point: If there was doubt about whether the above ECG findings are diagnostic — then ECG #1 should have been repeated within 15-20 minutes, rather than sending the patient to the Waiting Room, and not repeating the ECG for an hour.
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| Figure-1: Comparison between the 2 ECGs in today's case. (To improve visualization — I've digitized the original ECG using PMcardio). |
The Repeat ECG:
As per Dr. Meyers — lead-to-lead comparison of ECG #2 with ECG #1 leaves no doubt about the diagnosis of an acutely evolving infero-postero STEMI.
- Learning Point: The BEST way to improve our ability at recognizing less obvious but important subtle findings early on, is to go back to the initial ECG and compare lead-by-lead how the initial ECG evolved. That the disproportionately large T waves in leads II and aVF of the initial tracing were hyperacute is now proven by what the ST-T waves in these leads have become. Even the subtle ST segment straightening in lead III of the initial ECG was a harbinger of the marked ST elevation now seen in lead III of ECG #2.
- Similarly — the subtle-but-real ST segment straightening highlighted in lead V2 of ECG #1 — has now evolved to a more acute-appearing downsloping ST segment in ECG #2.
- Sombering Reality: Just as we saw in the recent March 17, 2025 post in Dr. Smith's ECG Blog — "quality control" of today's case will view physician recogition of STEMI criteria in ECG #2 as a "correct" interpretation — whereas STEMI criteria should never have developed because the cath lab should have been immediately activated as soon as the physician saw ECG #1.
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