Pericardial effusion

Pericardial effusion
A 2D echo transthoracic echocardiogram of pericardial effusion. The "swinging" heart.
Specialty	Cardiac surgery

A pericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. The pericardium is a two-part membrane surrounding the heart: the outer fibrous connective membrane and an inner two-layered serous membrane. The two layers of the serous membrane enclose the pericardial cavity (the potential space) between them.^[1] This pericardial space contains a small amount of pericardial fluid, normally 15-50 mL in volume.^[2] The pericardium, specifically the pericardial fluid provides lubrication, maintains the anatomic position of the heart in the chest (levocardia), and also serves as a barrier to protect the heart from infection and inflammation in adjacent tissues and organs.^[3][4]

By definition, a pericardial effusion occurs when the volume of fluid in the cavity exceeds the normal limit.^[5] If large enough, it can compress the heart, causing cardiac tamponade and obstructive shock.^[6] Some of the presenting symptoms are shortness of breath, chest pressure/pain, and malaise. Important etiologies of pericardial effusions are inflammatory and infectious (pericarditis), neoplastic, traumatic, and metabolic causes. Echocardiogram, CT and MRI are the most common methods of diagnosis, although chest X-ray and EKG are also often performed. Pericardiocentesis may be diagnostic as well as therapeutic (form of treatment).