UMEM Educational Pearls - By Leen Alblaihed

Category: Administration

Title: Pericarditis vs STEMI

Keywords: STEMI, pericarditis, (PubMed Search)

Posted: 6/11/2023 by Leen Alblaihed, MHA, MBBS (Emailed: 6/12/2023)
Click here to contact Leen Alblaihed, MHA, MBBS

a 37 year old patient comes in with chest pain, you obtain the following ECG. Is this a STEMI or Pericarditis? 



How can you tell? well, you follow the algorithm Dr. Mattu taught us....



The ECG above, if you go through the algorithm you will see that it is most likely pericarditis. 

note that PR depression can be transient and you might not see them. 

When in doubt, it is not wrong to consult cardiology. Getting serial ECGs also is important, STEMIs will usually evolve. 



52 yo M with chest pain and shortness of breath, ECG as shown, do you activate cath lab?

The posterior descending artery (PDA) supplies the posterior third of the interventricular septum, including the posterior and inferior walls of the left ventricle. The vessel most commonly originates from either the right coronary artery (right dominant), left circumflex artery (left dominant), or both (codominant).


Posterior MI frequently occurs as an extension of an inferior or lateral infarct. Isolated posterior MI occurs in 3 - 5% of cases (1), and is frequently missed on ECGs.

The posterior myocardium is not directly visualized on a standard 12 lead ECG, but reciprocal changes of STEMI in the anteroseptal leads (V1- V3) are seen (the posterior electrical activity is recorded from the anterior side of the heart) 


If in V1- V3 you see 


* ST segment depression 

* Tall R wave

* Upright T waves




Consider posterior MI as a cause. You need to then obtain an ECG with posterior leads. If there is  0.5 mm elevation in any posterior lead this is diagnostic of posterior MI.


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