Checkmark sign

How to distinguish pericarditis from STEMI

The Problem

Diffuse, convex (up) ST segment elevations with or without PR-segment depressions can be seen in both pericarditis or ST-segment Elevation Myocardial Infarction (STEMI), particularly if the patient has a wraparound LAD which supplies the inferior wall. So how can one reliably distinguish pericarditis from STEMI?

The Solution

If any of the following are present, a STEMI is more likely:

  • reciprocal ST depressions in any leads other than V1 or aVR. Pay particular attention to aVL which, in patients with inferior wall STEMI, may show T-wave inversion or  extremely subtle reciprocal ST depression.
  • straight or concave (“tombstone”) ST segments
  • QR-T complexes (“checkmark sign”)
Checkmark sign
Checkmark sign

Only if none of the above are present, then the following increases the likelihood of pericarditis:

  • Downsloping of TP-segment, or of entire QRSTP segment, particularly in Lead II (Spodick’s sign)
  • PR-segment depressions in multiple leads (seen in viral pericarditis).

Myths and Realities

Myth: only pericarditis causes convex (up) ST segments
Reality: Convex ST segments can be seen in STEMI as well

Myth: pericarditis causes only defuse ST elevations
Reality: Pericarditis causes localized ST elevations as well

Myth: only pericarditis causes defuse ST elevations
Reality: diffuse ST elevations can be see in STEMI as well

Myth: only pericarditis causes PR depressions
Reality: PR depressions are common in STEMI as well

Myth: only pericarditis causes PR segment elevation in aVR.
Reality: PR segment elevation in aVR can be seen in STEMIs as well

Myth: pericarditis can be almost always be distinguished from STEMI on EKG
Reality: a single EKG is often insufficient. Tough cases may require serial, history and physical examinations, electrocardiograms, troponins, an echocardiograms and sometimes cardiac catheterization.

References

Comments

3 responses to “How to distinguish pericarditis from STEMI”

  1.  Avatar
    Anonymous

    very helpful thank you for your efforts

    1. Mark Yoffe MD Avatar

      You are very welcome. I’m glad this helps!

  2. Mario Binder Avatar
    Mario Binder

    Dude, you are mixing up concave and convex…

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