This was sent by Kirk Lufkin and was diagnosed by a Physician Assistant who works with him by the name of Danielle Hutcheson. They work in a remote hospital without PCI capability. Kirk and I graduated from residency together in 1990, and he has taken up the OMI paradigm with enthusiasm. He showed Danielle the blog and she has started reading it regularly.
Case
A 50-something male with HTN, past smoker, no h/o CAD presented with chest pain. Here is the first Emergency Dept EKG:
What do you think?
Smith: there is ST depression in V2 - V6. It is maximal in V3. This is diagnostic of a posterior OMI. There is also T-wave inversion with ST depression in aVL. The inferior T waves are suspiciously large. The inferior leads alone plus aVL are extremely suspicious for an inferior OMI. If you put it all together, it is absolutely diagnostic of inferior posterior or OMI.
Danielle immediately saw it, and showed it to Kirk.
Would you give thrombolytics in this situation?
Danielle and Kirk were very certain of their diagnosis. There were no contraindications to thrombolytics, so they did administer thrombolytics with a door to needle time of 18 minutes.
They then recorded a posterior ECG:
V2 and V3 prove that the artery is persistently occluded.
Therefore, one might expect that leads V7-V9 would have some ST elevation.
However, there is no ST elevation in V7-V9.
The amount that is supposedly required for the diagnosis is 0.5 mm in two consecutive leads.
The PMCardio Queen of Hearts AI Model of course gets it right:
When to record posterior leads
I have always recommended that if the standard 12 lead EKG is diagnostic of posterior OMI, do not bother recording posterior leads, or if you do, do it only out of curiosity, and not to verify your diagnosis. If you think it is NOT a posterior OMI, but rather subendocardial ischemia, it can be useful to verify ST depression of the posterior wall. If you have a non-diagnostic standard 12 lead, posterior leads may reveal a posterior OMI that you did not suspect, as it can (rarely) reveal unexpected posterior ST Elevation.
Here is another case just posted this week by Robert Herman on his new substack: https://ecgs.substack.com/p/inferior-stemi-posterior-leads
ECG shown in Robert's post:
Note the subtle hyperacute T-waves in inferior leads (inferior OMI), the negative T-wave in V2 which confirm additional posterior OMI, and the absence of STE in posterior leads V7-V9. This was a proven inferior posterior OMI.
The PMCardio Queen of Hearts also gets this one correct (without posterior leads):
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Case Continued
They prepared the patient for transfer to a PCI center.
Door to transfer time was 48 minutes.
Another ECG was recorded by the paramedics just as they were leaving:
Findings are all improving, but still residual.
At angiogram, there was an RCA culprit. It was stented.
Peak troponins and echo are not available.
The cardiologist responded that he would not have given thrombolytics unless posterior leads showed ST Elevation.
Learning Points:
1. You should be more certain of OMI diagnosis when giving thrombolytics because they are more dangerous than PCI. Even in low risk patients, the risk of intracranial hemorrhage is nearing 2%. But if the clinical and ECG diagnosis is certain, there need not be ST Elevation meeting millimeter criteria. This means that you must be expert at the diagnosis, or use the Queen of Hearts.
2. Posterior leads frequently have false negatives. If the standard 12-lead is diagnostic, do not let absence of posterior ST Elevation dissuade you.
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