pericardial friction rub

Full Definition

Pericardial friction rub is a pathognomonic sign of pericarditis, characterized by a scratchy, high-pitched sound that varies with the cardiac cycle. It typically has three components corresponding to atrial systole, ventricular systole, and ventricular diastole, though often only one or two components are audible. The rub is best heard with the patient sitting forward and holding their breath in expiration. It may disappear when a pericardial effusion develops, as the fluid separates the inflamed pericardial layers.

Usage

Usage note: Distinguish from pleural friction rub, which varies with respiration rather than cardiac cycle.

In Context

• "A three-component pericardial friction rub was audible throughout the precordium." — Physical examination note
• "The pericardial friction rub disappeared after pericardiocentesis revealed 500mL of fluid." — Post-procedure note