n. the presence of blood within the membranous sac (pericardium) surrounding the heart, which may result from injury, tumours, rupture of the heart (e.g. following myocardial infarction), or a leaking aneurysm. The heart is compressed (see cardiac tamponade) and the circulation impaired; a large fall in blood pressure and cardiac arrest may result. Surgical drainage of the blood may be life saving.
Subjects: Medicine and Health.