Sunday, March 31, 2024

What happened after the Cath lab was activated for a chest pain patient with this ECG?

Sent by anonymous, written by Pendell Meyers

I received a text with this image and no other information:

What do you think?

I simply texted back:  "Definite posterior OMI." The person I was texting knows implicitly based on our experience together that I mean "Definite posterior OMI, assuming the patient's clinical presentation is consistent with ACS."

The patient was a middle-aged female who had acute chest pain of approximately 6 hours duration. The pain was still active at the time of evaluation.

Queen of Hearts:

You can see that the Queen is most concerned with the ST depression in V2 and V3

The physician activated the cath lab and the patient was transported to the cath lab.

The interventional cardiologist then canceled the activation and returned the patient to the ED without doing an angiogram ("Not a STEMI").

I advised that perhaps posterior leads would help to persuade the interventionalist, since the 2022 ACC recommendations include posterior STEMI as a formal STEMI equivalent, but only officially by 0.5 mm STE in the posterior leads. 

So here is a posterior ECG (unfortunately, I am not sure where exactly the precordial leads are, but suffice to say that at least some of leads V2-V6 are posterior leads):
Limb leads also reversed. Leads V3-V4 are clearly posterior leads and have more than 0.5 mm of STE.

Despite the ACC guidelines for posterior STEMI, the cardiologist again refused to take the patient to the cath lab.

Only when the first troponin (high sens trop I) returned at around 22,000 ng/L did the cardiologist reconsider. 

Angiogram reportedly showed acute thrombotic occlusion of the first obtuse marginal which was stented.

Peak troponin was not recorded. 

The patient survived the hospitalization.

Long term follow up is unavailable.

The Queen of Hearts PM Cardio App is now available in the European Union (CE approved) the App Store and on Google Play.  For Americans, you need to wait for the FDA.  But in the meantime:


If you want this bot to help you make the early diagnosis of OMI and save your patient and his/her myocardium, you can sign up to get an early beta version of the bot here.  It is not yet available, but this is your way to get on the list.

 Learning Points

Posterior STEMI is now a formal STEMI equivalent in USA per the ACC, but they only specify it as STE in posterior leads. They have not yet caught up to the literature we have published showing that ST depression maximal in V1-V4 (without another reason, such as abnormal QRS, etc) is specific for posterior OMI in the setting of ACS symptoms:

Ongoing ischemic symptoms in NSTEMI is already an indication for emergent cath, regardless of the ECG.

Sometimes posterior leads help, and sometimes they falsely reassure. 

See some relevant cases below:

Chest pain with anterior ST depression: look what happens if you use posterior leads.

A woman in her 50s with chest pain and lightheadedness and "anterior subendocardial ischemia"

MY Comment, by KEN GRAUER, MD (4/1/2024):

I couldn’t resist making this figure … Even more impressive than posterior leads — Isn’t this Mirror Test absolutely diagnostic of acute posterior OMI in this patient with CP? 
  • For more on the Mirror Test — Please see My Comment in the September 21, 2022 post in Dr. Smith’s ECG Blog.

  • As per Dr. Meyers above — a definite Posterior OMI ...

Figure-1: Mirror-image of leads V1,2,3 from ECG #1.

No comments:

Post a Comment

DEAR READER: I have loved receiving your comments, but I am no longer able to moderate them. Since the vast majority are SPAM, I need to moderate them all. Therefore, comments will rarely be published any more. So Sorry.

Recommended Resources