A 32-year-old woman presented to the ED with shortness of breath and a dry cough. She had recently had a cold, but all of her symptoms, including fever, sore throat, and runny nose, had since resolved. She denied any chest pain, leg swelling, or other complaints.
Vital signs were normal except for a respiratory rate of 22 bpm. Her physical exam was normal except for some mild jugular vein distention with no rales, wheezes, or leg edema.
The initial differential diagnosis included pneumonia, congestive heart failure, myocarditis, and pulmonary embolism.
Her CBC, HCG, and BMP were normal. A chest x-ray showed borderline cardiomegaly. Her ECG is shown.
Pericardial effusions are usually painless, and can present with dyspnea and generalized weakness. Additional symptoms may include palpitations, sweating, syncope, near-syncope, and, of course, chest discomfort. The most common findings on physical exam are pulsus paradoxus, tachycardia, and JVD. Other findings tend to be quite insensitive.
The diagnostic test of choice for a significant pericardial effusion is an echocardiogram, but chest x-ray and ECG will also suggest it. A large cardiac silhouette, especially if it is boot-shaped, is suggestive of a pericardial effusion. On the ECG, low voltage is the most sensitive finding. If the effusion is new (as was the case for our patient), start with an echocardiogram to rule out a large pericardial effusion as the cause of low voltage. The echocardiogram of our patient showed one. (See echo image below.) An effusion is even more likely if it is or could be new or if the patient has otherwise unexplained tachycardia. Electrical alternans may also be present but is not sensitive.
Tamponade is suggested by tachycardia, diastolic right ventricular collapse, systolic right atrial collapse, or systolic left ventricular wall "kissing." See sample page below for the differences between subacute tamponade, which is more common, and acute tamponade, which is rarer but deadlier and is usually caused by trauma or aortic dissection. Treatment of pericardial effusions depends on the cause and the severity.
The patient was diagnosed with idiopathic pericarditis with a large effusion. She was admitted for observation and remained stable. She was started on colchicine and aspirin and did well.
Source: The Tarascon Emergency Department Quick Reference Guide