Review Question - QID 104043

This clinical presentation is consistent with acute pericarditis. This pericarditis is most likely due to underlying systemic lupus erythematosus (SLE), for which the ANA test would be a first step.

Pericarditis refers to inflammation of the pericardial sac and can be caused by viruses (most commonly), bacterial infections, malignancy, or autoimmune disorders. The diagnosis of acute pericarditis is suspected based on a history of the characteristic pleuritic chest pain, which improves with leaning forward, and when a pericardial friction rub is auscultated. Acute pericarditis is associated with ECG findings of diffuse ST elevations and PR depressions in the left chest leads. Chest radiography is typically normal in patients with acute pericarditis, but the cardiac silhouette may enlarge if at least 200 mL of pericardial fluid accumulates.

Snyder et al. state that acute pericarditis is found in approximately 5% of patients admitted to the emergency department for chest pain unrelated to myocardial infarction. First-line therapies include nonsteroidal anti-inflammatory drugs (NSAIDs) and colchicine, with glucocorticoids being reserved for severe or refractory cases.

LeWinter states that in developed countries, 80 to 90% of cases of acute pericarditis are idiopathic and presumed to be viral. He further states that 70 to 90% of cases of acute pericarditis will respond to a combination of NSAIDs and colchicine and that treatment with glucocorticoids can actually increase the risk of recurrence of pericarditis.

Figure A shows a representative ECG of pericarditis, with diffuse concave ST elevation and PR depression in the precordial (V2-6) and limb (I, II, aVL, aVF) leads. Figure B shows a normal chest radiograph, the most common radiographic finding in acute pericarditis. Illustration A shows a chest radiograph exhibiting cardiomegaly due to a pericardial effusion, which is sometimes seen in acute pericarditis. Illustration B lists the most common causes of acute pericarditis.

Incorrect Answers:
Answer 1: While an abnormal complete blood count can be seen in SLE (anemia, leukopenia, thrombocytopenia), this would not be diagnostic of SLE.
Answer 2: Rheumatoid factor can be positive in approximately 20% of patients with SLE, but would not be diagnostic of SLE. Rheutmatoid arthritis is a potential underlying etiology of pericarditis, but is unlikely given this clinical scenario.
Answer 4: Parathyroid hormone would be expected to be normal in this patient.
Answer 5: Antineutrophil cytoplasmic antibody is positive in only 0-1% of patients with SLE and would not be diagnostic in this case.