While pericarditis is an unusual diagnosis, with an annual incidence of 27.7 per 100,000 persons, the recurrence rate of almost 30 percent is surprisingly high.1 Many of the patients diagnosed with acute pericarditis in the emergency department (ED) will relapse and some will develop debilitating, chronic, constrictive pericarditis. The mortality rate of 1.1 percent in developed countries is also significant.1 The good news is that timely diagnosis and appropriate treatment options have been shown to decrease recurrence rates and help prevent chronic complications.2 However, considering that the clinical presentation, electrocardiogram (ECG), and laboratory findings may be confused with more deadly causes of chest pain such as myocardial infarction (MI), aortic dissection, and pulmonary embolism, pericarditis should be considered a diagnosis of exclusion in the ED. Here are some practical tips on how to distinguish pericarditis from more deadly causes of chest pain and a review of the literature on time-sensitive treatment that reduces recurrence and complications of pericarditis.
Explore This IssueACEP Now: Vol 41 – No 07 – July 2022
What Sets Pericarditis Apart?
The clinical presentation of pericarditis overlaps with MI, pulmonary embolism, and aortic dissection, but usually includes several features that can help distinguish it from these more deadly causes of chest pain. Persistent chest pain for weeks is not typical for these other deadly diagnoses and should raise suspicion for pericarditis. Pericarditis can occur at any age, and these other deadly diseases can occur in young patients, however, young, otherwise healthy patients with chest pain and no risk factors for MI, aortic dissection, or pulmonary embolism should raise the suspicion for pericarditis. A respiratory or gastroenterological viral prodrome that may include malaise, myalgias, and low-grade fever is common in patients with acute pericarditis and less common in patients with MI.
Chest pain in patients with pericarditis is typically central, pleuritic, sharp, worse on lying supine, and better on sitting up and leaning forward. The pleuritic chest pain of pericarditis is usually central and diffuse as opposed to pulmonary embolism and pneumothorax where the pain is usually lateralized and focal. Sometimes the pain radiates to the back, neck, or shoulder, as in patients with MI. Radiation to the trapezius ridge is common. A cardiac friction rub—while traditionally thought of as highly specific for pericarditis—may be falsely identified in hirsute patients when chest hair rubs against the stethoscope with rise and fall of the chest during auscultation. Despite these distinguishing features, however, there is no group of clinical features with sufficient specificity to rule in pericarditis with certainty, underlining the concept that it should be considered a diagnosis of exclusion. It is important to realize, as well, that pericarditis may occur concurrently with aortic dissection and MI.