What is it?
Acute pericarditis is, as the name would imply, an inflammation of the pericardium. The vast majority of these cases are idiopathic, but assumed to be due to a virus. The other 10-20% can have a specific cause such as connective tissue disease (SLE), cancer, or post-MI syndromes. Its true incidence is not known because mild cases may never be diagnosed, but it does make up around 5% of patients who will present to the ED with chest pain.
Why do I care?
Acute pericarditis is usually a self-limited condition with a low (~1%) mortality rate. Although 1/3 of cases may be associated with myocarditis, clinical heart failure and arrhythmias are rare at time of presentation. Further, the long-term prognosis for both idiopathic pericarditis and associated myocarditis is excellent. Even so, specific therapies are indicated for pericarditis and mismanagement of the condition can lead to its recurrence. It is still therefore important to recognize and treat this appropriately.
What do I need to know?
First step is making the diagnosis. To do this you need at least 2 of the following 4 criteria.
1. Chest pain consistent with pericarditis (ie - pleuritic chest pain that improves by leaning forward)
2. Pericardial friction rub (difficult to hear and inconsistent even when present)
3. Typical ECG signs (PR depressions and diffuse ST elevations)
4. Pericardial effusion (importance of learning and being efficient in bedside echo)
The diagnosis may not always be clear, and other causes of pleuritic chest pain may need to be excluded. If other causes are excluded and pericarditis is not confirmed, but remains the most likely, it should be treated as per recommendations.
Pericarditis may be idiopathic, but as mentioned above, can be seen in other specific conditions as well. The major considerations should be systemic lupus erythematous. Think about this as a possibility of any patient with SLE, or that fits with its classic demographics (young female).
What do I need to do?
A atypical chest pain workup should suffice for the majority of these patients. While sending a troponin is sometimes debatable, it is generally recommended. This will help to determine if co-existing myocarditis is present. This is important to consider for the young patient you might have only ordered a CXR and ECG on otherwise. CRP can be sent as well for evidence of inflammation, but remember it is not a specific test. A bedside or official echo should be done to evaluate for effusions. Pericardiocentesis does not need to be done unless there is tamponade. Further testing such as cardiac CT or MRI can be done, but often not necessary for uncomplicated pericarditis.
The recommended treatment options currently consist of NSAIDs and colchicine. A PPI should also be prescribed for gastric protection. Steroids are not recommended due to high rates of reoccurrence when prescribed. An exception would be for SLE.
Options for NSAIDs - duration of therapy 1-2 weeks
- ibuprofen 600-800 mg every 6-8 hours
- indomethacin 25-50 mg every 8 hours
- aspirin 2-4 grams daily divided BID
Colchicine - duration of therapy 3 months
- 0.5 mg daily if < 70 kg
- 0.5 mg BID if > 70 kg
Unless there is a large effusion, evidence of tamponade, or a worrisome secondary cause of pericarditis, patients can be safely discharged home with outpatient follow up.
A little longer post than my others, but lots of good stuff here. For the podcast version of this, check out the Cardiology Corner section of the July edition of EM:RAP. Thanks for reading, now go save some lives.
LeWinter MM. Clinical practice: acute pericarditis. N Engl J Med. 2014 Dec 18;371(25):2410-6.
Submitted by Dr. Michael Craddick, PGY-2