Pericardial Effusion

Excerpt

A pericardial effusion refers to the accumulation of fluid in the pericardial sac surrounding the heart. The pericardial sac is composed of the thin visceral pericardium which consists of a single layer of cells adherent to the cardiac epicardium and the thicker, fibrous parietal pericardium composed of collagen and elastin which is adherent to the lungs, diaphragm, sternum, great vessels, and other mediastinal structures surrounding the heart. In a healthy individual, the pericardial sac contains between 15 mL and 50 mL of serous fluid.