What does a pericardial friction rub signify?

• A. Infection of the endocardium.
• B. Pulmonary hypertension.
• C. Inflammation of the pericardium, often associated with pericarditis.
• D. Obstruction of a coronary artery.

Answer: (C)

A pericardial friction rub signals inflammation of the pericardium, i.e., pericarditis. The sound comes from the roughened inner surfaces of the inflamed pericardial layers rubbing against one another as the heart moves, producing a scratchy, high-pitched noise. It’s usually heard best at the left lower sternal border when the patient sits up and leans forward, and may be louder with expiration. This sign ties directly to pericardial inflammation and can accompany chest pain that is often pleuritic or improved by sitting up and forward. It helps distinguish pericardial inflammation from problems like endocardial infection, pulmonary hypertension, or coronary artery obstruction, which do not produce a pericardial friction rub.