We should all be able to recognize the pericardial friction rub. Our patient, about a week ago, had a respiratory infection. Now he has somewhat sharp chest pain, relieved by sitting up. Let’s listen to our patient at the lower left sternal edge, where in this patient the rub is the loudest. We’ll time the events with the systolic impulse of the carotid vessel by looking at the cotton swab. Everyone listen together and also watch respiration. [sounds]
Our patient has a classic 3-component friction rub [sounds]. You mimic that [sounds]. In our case, it got a bit louder with expiration, but it could get louder with inspiration or not change at all. Now, what is the cause of those components? Well, it’s when the heart moves within the pericardial sac, during systole, during contraction, during rapid filling in early diastole and during late diastolic filling. You must have at least two components to diagnose a friction rub. One more time, mimic [sounds]. A pericardial friction rub.
Pericardial Friction Rub Components
Pericardial friction rubs are due to inflammation of the pericardial sac. They are best heard with the patient leaning forward at the end of forced expiration using the diaphragm of the stethoscope. Rubs are often most prominent between the lower left sternal edge and apex. They are high pitched and scratchy in quality and are often subtle and vary in intensity.
Pericardial Friction Graphic
The classic pericardial friction rub has three components: a systolic component during ventricular contraction; a presystolic, or late diastolic, component at the time of atrial systole; and an early diastolic component during rapid ventricular filling. Two components should be present to diagnose a rub, as a single component systolic rub cannot be reliably differentiated from a scratchy systolic murmur.