Pericarditis: Clinical sciences

Pericarditis is inflammation of pericardium, sometimes associated with the accumulation of fluid, known as a pericardial effusion. The underlying inflammation might be due to viral infection, uremia, autoimmune disease, or after trauma, but regardless of cause, is associated with severe chest pain due to the pericardium’s abundant nerve supply.

Additionally, pericarditis may lead to the development of dangerous complications, such as pericardial effusion, which is characterized by accumulation of fluid around the heart; as well as cardiac tamponade, where the accumulated fluid compresses the heart.

So, if you suspect pericarditis or one of its complications, first you should perform an ABCDE assessment, to determine if your patient is unstable or stable. If the patient is unstable, stabilize the airway, breathing, and circulation, which typically requires obtaining IV access and intubating the patient if you need to secure the airway.

Next, perform a focused history and physical examination. On physical exam be on the lookout for Beck triad, which includes hypotension, jugular venous distension, and muffled heart sounds. Additionally, a physical exam might reveal pulsus paradoxus, which is when the systolic blood pressure drops with inspiration, and no audible pericardial friction rub.

All of these findings should lead you to suspect that a large pericardial effusion has resulted in cardiac tamponade, so your next step is to order an ECG and chest x-ray immediately to evaluate your suspicions. Alternatively, if available, perform point of care ultrasound, or POCUS for short.

ECG typically shows sinus tachycardia with low QRS voltage and electrical alternans, defined as beat-to-beat variation in the QRS amplitude. This occurs as a result of swinging of the heart in the pericardial fluid, which can be seen with a large pericardial effusion. On the other hand, chest x-ray might show an enlarged cardiac silhouette with clear lung fields. Finally, you can use POCUS to directly visualize pericardial effusion and detect collapse of the right sided cardiac chambers. These findings confirm the diagnosis of pericardial effusion and cardiac tamponade. On the flip side, if you do not find any evidence of effusion or cardiac tamponade, then consider an alternate diagnosis.