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KEY QUESTIONS
- What features differentiate acute pericarditis from ST-elevation myocardial infarction?
- What are the criteria for diagnosing acute pericarditis?
- What are the treatment options?
What features differentiate acute pericarditis from ST-elevation myocardial infarction?
Differentiating pericarditis from ST-elevation myocardial infarction (STEMI) can be challenging. However, features that suggest pericarditis over STEMI include any of the following: diffuse concave-up ST elevations without reciprocal changes; PR depression; PR elevation in aVR; ST-elevation in lead II greater than lead III; and Spodick’s sign—down-sloping of the TP segment. It is important to note that the test characteristics of any single electrocardiographic feature are insufficient to rule in/out pericarditis, and that the feature with the highest odds ratio for predicting STEMI is reciprocal ST-depressions (Figure 1).
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The first 2 weeks are characterized by the above findings. Over several weeks, the ST elevation resolves and the T waves flatten. Next, the T waves invert. Finally, over several weeks, the ECG returns to the patient’s baseline (Figure 2).
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What are the criteria for diagnosing acute pericarditis?
The diagnosis is made by meeting two of four criteria:2,3
- Typical symptoms (pleuritic sharp chest pain better when leaning forward)
- New pericardial effusion
- Presence of friction rub
- Typical ECG findings
What are the treatment options?
Colchicine for 3 months and NSAIDs/aspirin tapered over 3-4 weeks are first-line in patients without contraindications.4 It’s reasonable to prescribe a proton pump inhibitor, also. Corticosteroids are reserved for patients with colchicine/NSAID/aspirin contraindication and are not preferred as they are associated with increased recurrence.3
Pearls for Urgent Care Management
- Electrocardiographic features of acute pericarditis include diffuse concave-up ST elevations without reciprocal changes, PR depression, PR elevation in aVR, ST-elevation in lead II greater than lead III, and Spodick’s sign—down-sloping of the TP segment
- Treatment includes 3 months of colchicine and NSAIDs tapered over 3-4 weeks
- Uncomplicated, stable patients with acute pericarditis do not need to be transferred to a higher level of care and can be managed in the outpatient setting
- If the diagnosis is in question, or there are complicating features (eg, instability), transfer to a higher level of care is appropriate
See the video provided by ECG Stampede for detailed analysis.
References
- Witting MD, Hu KM, Westreich AA, et al. Evaluation of Spodick’s sign and other electrocardiographic findings as indicators of STEMI and pericarditis. J Emerg Med. 2020;58(4):562-569.
- Wagner GS, Strauss DG. Marriott’s Practical Electrocardiography. 12th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2014.
- LeWinter MM. Acute pericarditis. N Engl J Med. 2017;371(25):349-359.
- Imazio M, Brucato A, Cemin R, et al. A randomized trial of colchicine for acute pericarditis. N Engl J Med. 2013;369(16):1522-1528.
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