Pericardial rub

Differential diagnosis

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. Also, a pleural rub can only be heard during inspiration, whereas, the pericardial rub can be heard even after cessation of breathing. Pleural rub creates pain mostly on the lateral part of the chest wall, whereas pain due to pericardial rub is always central in location. The intensity of pleural rub is increased on pressing the diaphragm of the stethoscope over the affected area, whereas there is no such change in case of a pericardial rub.