Thread by @EM_RESUS

Here’s a great #ECG of a man who presented to the ER with crushing chest pain.

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Here’s the ECG Computer Read:

"Non-specific ST abnormality, consider anterior subendocardial ischemia."

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Take a good look at Leads V1-V3 and burn these morphologies and this pattern into your mind.

THIS is what Posterior #STEMI looks like on a Standard 12-Lead ECG!

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But how can you have a STEMI without ST Elevation?

Because in addition to viewing the Anterior Septum, these leads also happen to be positioned directly opposite of the Posterior Wall. So they reflect OPPOSITE of what is happening to the POSTERIOR myocardium!

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A helpful trick is to turn the ECG backwards & flip it upside down.

Now you can see EXACTLY what is ACTUALLY happening to the Posterior Myocardial Wall!

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The other thing you can do is to record “Posterior Leads”

This simply entails taking any three precordial leads and positioning them beneath the patient’s left scapula as pictured here. V7-V9 now look directly at the Posterior Wall!

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Here is the Posterior #ECG of our patient. Leads V4-V6 have been moved to the back and are now V7-V9.

You can see the ST Elevations in these leads further confirming the diagnosis of Posterior #STEMI !

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Importantly, the diagnosis of Posterior STEMI should generally be made on Standard ECG and Posterior Leads should NOT be heavily relied upon.

The reason for this is that (esp. if the patient is very muscular, obese etc.) Posterior Leads are often falsely negative!

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Back to our patient, the Cath Lab was activated right away. Here are are some beautiful before & after shots of the angiogram revealing the culprit:

A 100% Circumflex Occlusion that as you can see was very nicely reperfused!

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Sadly, simply because it presents differently on Standard 12-Lead #ECG, Posterior #STEMI is the most commonly missed of all Acute Coronary Occlusions!

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But it doesn’t have to be. It just takes spreading knowledge and awareness to make a change.

So please remember the concepts I’ve shared in this thread and share them with others. I promise you will save lives.

#FOAMed

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