ST-Depression in EKG -- Question

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Hope you don't mind a question from a medic here but figured I could get some feedback from EM physicians on the matter.

If you have an EKG with significant ST depression, typically in the anterior and lateral leads, the old trick is to flip it over and upside down. This will give a posterior view of the heart and show the original ST depression as ST elevation.

My question is based on your experience, is this a reliable method for determining an acute MI in a patient with clinical findings that indicate ischemia/infarction such as CP, N/V, diaphoresis, etc? Do you confirm with a posterior EKG ("nine on the spine")?

I use this trick a lot and have activated STEMI alerts in the field numerous times with pretty good results. I am just curious how often practicing physicians use this and how accurate it really is.

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Safe answer: Shortcuts are not the same thing as doing the assessment. It may be useful at times (I dont doubt it), but its not a substitute.
Complete answer: I dont have NEARLY enough knowledge or experience to weigh in, but I've had attendings respond in this way to a similar suggestion by other residents.

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I like this article for left main STEMI equivalents:

http://lifeinthefastlane.com/ecg-library/lmca/

I have seen V7-9 done but have never personally done it.. . you usually figure out that the patient needs to go to the cath lab emergently based on the initial 12-lead, focused h&p and medical records. To answer your question: most of attendings I work with do not regularly flip around the EKG or get posterior leads.. you can see the LMCA concerning ST depression right there without messing with it.. the flip is more of an educational trick. So I can't really say if it's reliable, lol. Understanding acute atypical EKG findings concerning for ischemia is reliable but complex and involves a lot more than changing the position of the paper.

I had one of these the other day, CP w/ anteriorlateral concordant ST depression and almost 1mm STE in aVR. not technically a stemi but the EKG obviously looks terrible.

He went to PCI <20 minutes after ED arrival.
 
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Thanks for the feedback.

This trick was actually taught to me by a EM physician early in my medic training years ago. It seems like it is a very old-school trick but based on only my purely anecdotal evidence, it appears to be a pretty good trick with decent reliability.

And I will completely agree that understanding EKG changes is more important than a simple paper flip. I teach cardiology for medics and nurses at local colleges and training centers. I try to beat them to death with understanding EKG basics. After that, it is much easier to pick up abnormalities and not classify everything as a FLB.
 
I don't routinely flip the EKG or get a posterior leads.

A posterior MI is a mirror image of an anteroseptal MI. So... in leads V1-V2 you will see:
-large R-waves instead of Q-waves
-ST depression instead of ST elevation
-upright T waves instead of T wave inversions

If in doubt, I would theoretically get a posterior EKG which I've done a few times mainly for educational purposes.

Also, posterior STEMI's are often associated with inferior STEMI's (RCA/circumflex involvement)
 
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Obviously look at the clinical picture, and look at old ECGs, but you can't diagnose a posterior STEMI without actually having the ST elevation. You can do the posterior leads and if you see it then you've got your diagnosis. Most of the time it will be associated with an inferior STEMI (with posterior involvement) so it becomes a moot point and more academic, because you're already treating for it based off the interior leads.
 
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