The pericardial knock is heard in early diastole and is associated with sudden cessation of rapid ventricular filling.

This statement is **true**. The lecture describes the **pericardial knock** as a high-pitched sound in early diastole, produced when rapid ventricular filling abruptly ceases because the constricting pericardium limits further expansion. It is a classic auscultatory finding of constrictive pericarditis. It should not be confused with the scratchy friction rub associated with acute pericarditis. **Key takeaway:** An early-diastolic pericardial knock is a characteristic sign of constriction. **Glossary:** **Diastole**: the phase of cardiac relaxation and filling. **Auscultatory**: identified by listening to body sounds.