Healthy young patients often present to the Emergency Department with chest pain. These patients often have EKGs that show early repolarization, AKA J-point elevation. ST elevation can also mean STEMI – and so while it’s almost never a STEMI in the Pediatric Emergency Department, it could be one – and it’s important to be able to differentiate between the two.

What does a left anterior STEMI look like on EKG?

You can check out this fantastic resource from In general elevation of the ST segment in the following leads may suggest the location of the MI – but be warner that this correlation is often subject to error and is not always exactly what is seen on cath or autopsy:

  • Septal = V1-2
  • Anterior = V2-5
  • Anteroseptal = V1-4
  • Anterolateral = V3-6, I + aVL
  • Extensive anterior / anterolateral = V1-6, I + aVL

Since the left anterior descending artery in in the anterior portion of the heart then the precordial leads show elevation of the ST segments. Check out these sample EKGs and see if you can figure out where the ST changes are.

How can we tell the difference?

Since both can be seen in young patients, this handy dandy Paucis Verbis card from Academic Life in Emergency Medicine does a great job in distilling down the main differences between the two.

Early repolarization versus ST elevation from Academic Life in Emergency Medicine (

I hate math, make things easy on me?

OK, and so I totally am borrowing from MDCalc – but you can go there and use the calculator itself.
MD Calc


Dr. Smith’s ECG blog

Early Repolarization from Academic Life in Emergency Medicine

Smith et al., Electrocardiographic Differentiation of Early Repolarization From Subtle Anterior ST-Segment Elevation Myocardial Infarction, Annals of Emergency Medicine, 2012.