<unk>  progresses to cardiac tamponade when the accumulated fluid compresses the heart How much fluid is stored in the<unk> ricardial sac at one particular time is based on the balance between production and reabsorption. Studies have shown that much of the fluid that accumulates in the<unk> ricardial sac is from plasma filtration of the epicardial capillaries and a small amount from the myocardium, while the fluid that is drained is mostly via the parietal lymphatic capillaries.<unk>  usually results from a disturbed equilibrium between these two processes or from a structural abnormality that allows excess fluid to enter the<unk> ricardial cavity. Because of the limited amount of anatomic space in the<unk> ricardial cavity and the limited elasticity of the<unk> ricardium, fluid accumulation beyond the normal amount leads to an increased intrapericardial pressure which can negatively affect heart function. A<unk>  with enough pressure to adversely affect heart function is called cardiac tamponade.<unk> s can cause cardiac tamponade in acute settings with fluid as little as 150mL. In chronic settings, however, fluid can accumulate anywhere up to 2L before an<unk>  causes cardiac tamponade. The reason behind this is the elasticity of the<unk> ricardium. When fluid fills the cavity rapidly, the<unk> ricardium cannot stretch rapidly, but in chronic<unk> s, the gradual fluid collection provides the<unk> ricardium enough time to accommodate and stretch with the increasing fluid levels.
Pericardial effusion
Pericarditis
Cardiac tamponade
Subpulmonic effusion
Acute pericarditis
Pleural effusion
Constrictive pericarditis
Pneumopericardium