A pericardial friction rub
, also pericardial rub
, is an audible medical sign
used in the diagnosis
. Upon auscultation
, this sign is an extra heart sound
of to-and-fro character, typically with three components, one systolic
and two diastolic
. It resembles the sound of squeaky leather and often is described as grating, scratching, or rasping. The sound seems very close to the ear and may seem louder than or may even mask the other heart sounds. The sound usually is best heard between the apex and sternum
but may be widespread.
is a double-walled sac around the heart
, or inflammation
of the pericardium, causes the inner and outer (parietal and visceral) walls to rub against each other.
Pericardial friction rub is one of several, similar sounds. A differential diagnosis
may be possible, or not, depending upon the number of components that are audible. Pericardial friction rub may have one, two, or three audible components, whereas the similar pleural friction rub
ordinarily has two audible components. One- and two-component rubs are ambiguous. A three-component rub distinguishes a pericardial rub and indicates the presence of pericarditis.