Pericardial Effusions: Causes, Diagnosis, and Management.

The presentation of a patient with a pericardial effusion can range from an incidental finding to a life-threatening emergency. Accordingly, the causes of pericardial effusions are numerous and can generally be divided into inflammatory and non-inflammatory etiologies. For all patients with a suspected pericardial effusion, echocardiography is essential to define the location and size of an effusion. In pericardial tamponade, the hemodynamics relate to decreased pericardial compliance, ventricular interdependence, and an inspiratory decrease in the pressure gradient for left ventricular filling. Echocardiography provides insight into the pathophysiologic alterations, primarily through an assessment of chamber collapse, inferior vena cava plethora, and marked respiratory variation in mitral and tricuspid inflow. Once diagnosed, pericardiocentesis is performed in patients with tamponade, preferably with echocardiographic guidance. With a large effusion but no tamponade, pericardiocentesis is rarely needed for diagnostic purposes, though is performed if there is concern for a bacterial infection. In patients with malignancy, pericardial window is preferred given the risk for recurrence. Finally, large effusions can progress to tamponade, but can generally be followed closely until the extent of the effusion facilitates safe pericardiocentesis.