By Dr Adam Michael

Here are some key takeaways: 

1. 2 of the following 4 criteria are needed for the diagnosis of pericarditis:
   1. ​​​​​​​Typical chest pain
   2. Pericardial Friction Rub (most people have never heard one- but it sounds like a murmur)
   3. Typical ECG changes
   4. Non-trivial pericardial effusion.
2. When looking at the ECG, you need to start with the assumption that this is a STEMI
3. There are specific ECG criteria to distinguish STEMI from pericarditis:
   1. ST depression in any other lead except aVR and V1 assume a STEMI
   2. STE in III > II it is a STEMI
   3. Is there horizontal or convex up STE it is a STEMI
4. If we aren’t sure of these specific criteria for STEMI, we can then look for pericarditis changes which include: changes across multiple territories, notmal T waves, concave up STE, PR depression in multiple leads and a Spodick Sign.
5. A high troponin is also possible in patients with pericarditis. Usually the myocardium is involved. (My point added here: Remember that the percardium is electrically inert, so ECG changes must involve the heart muscle, so a raised troponin may occur)
6. Serial ECGs are very helpful
7. When things don’t make sense, ask for advice and go back to first principles.