From the Guidelines
The three components of a pericardial friction rub correspond to different phases of the cardiac cycle: atrial systole, ventricular systole, and early ventricular diastole. The first component occurs during atrial contraction when the atria contract against the ventricles. The second component, which is typically the loudest and most consistently heard, occurs during ventricular systole when the ventricles contract and rub against the pericardium. The third component happens during early ventricular diastole when the ventricles begin to relax and fill with blood. These sounds are produced by the inflamed pericardial surfaces rubbing against each other during cardiac movement, as noted in the guidelines on the diagnosis and management of pericardial diseases 1. Pericardial friction rubs are best heard with the diaphragm of the stethoscope while the patient leans forward and holds their breath after exhaling, as this brings the heart closer to the chest wall. The rub has a characteristic scratchy, grating quality that distinguishes it from other cardiac sounds and is a key diagnostic finding in pericarditis, further supported by the diagnostic pathway outlined in 2. Key points to consider in the diagnosis of pericarditis include:
- Auscultation for pericardial rub, which can be mono-, bi-, or triphasic 2
- ECG changes, including ST segment elevation and PR segment deviations 2
- Echocardiography to detect effusion and signs of tamponade 2
- Blood analyses for markers of inflammation and myocardial lesion 2
From the Research
Pericardial Friction Rub Components
The three components corresponding to different phases of the cardiac cycle in pericardial friction rub are:
- Atrial contraction component
- Ventricular contraction component
- Rapid filling or early diastolic component There are no research papers provided to assist in answering this question with specific details regarding these components, however, general knowledge of pericardial friction rub indicates the presence of these three components 3