Cardiac tamponade

Cardiac tamponade, also known as pericardial tamponade, is an acute type of pericardial effusion in which fluid accumulates in the pericardial space. This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial rupture, cancer, cardiac surgery, etc.

If the amount of fluid increases slowly (such as in hypothyroidism) the pericardial sac can expand to contain a liter or more of fluid prior to tamponade occurring. When the pericardial space fills up with fluid faster than the pericardial sac can stretch, this puts pressure on the heart. Rapid fluid accumulation may occur after trauma or myocardial rupture and as little as 100 ml can cause tamponade.