pericardial knock

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per·i·car·di·al knock

an early diastolic sound that is a variant of the third heart sound, but occurring distinctly earlier, due to rapid ventricular filling's being abruptly halted by the restricting pericardium; a true "knocking" quality is uncommon.

pericardial 'knock'

Cardiology A loud 3rd heart sound occurring when the ventricular filling abruptly stops at the end of the early diastolic pressure dip–ie, at the end of the rapidly filling phase of the ventricles; classically associated with severe constrictive pericarditis, or with penetrating trauma to the pericardium, the PK has a relatively high pitch, often ↑ in intensity with inspiration and coincides with the nadir of the 'y' descent of the jugular venous pulse, resembling a premature 3rd sound. Cf Gallop.


pertaining to the pericardium.

pericardial diaphragmatic hernia
pericardial effusion
the second stage of pericarditis when much inflammatory exudate accumulates, part of a general edematous state or in cases of neoplasia involving the epicardium or pericardium. Characterized by enlargement of the cardiac silhouette on radiography and outline on percussion, muffling of heart sounds and congestive heart failure due to compression of the heart by cardiac tamponade.
pericardial fibrosis
a chronic change in pericarditis, leading to constriction that limits diastolic ventricular volume. See also constrictive pericarditis.
pericardial friction rub
see pericardial rub.
pericardial inflammation
pericardial knock
an early diastolic sound caused by loss of pericardial elasticity accompanying fibrosis that limits ventricular filling.
pericardial meridian points
acupuncture points located along the pericardial meridian.
pericardial paracentesis
pericardial tamponade
see cardiac tamponade.