Physical Examination – Pericardial friction rubs are often due to inflammation of the pericardial sac, indicating a possible diagnosis of pericarditis. Assessment for a pericardial friction rub should be done with the diaphragm of the stethoscope placed at the 3rd interspace of the left lateral wall. The sound of the pericardial friction rub may be enhanced by having the patient lean forward and exhale.
The pericardial friction rub classically has three components.
1) Atrial Systole
2) Ventricular Systole
3) Ventricular Diastole
Pericardial friction rubs can be distinguished from pleural friction rubs in that it has 3 components rather than 2 as well as the fact that it can be heard even when the patient is asked to hold their breath, unlike pleural friction rubs which can be heard on inspiration and expiration only.