Which of the following symptoms is associated with constrictive pericarditis but not cardiac tamponade?

Kussmaul's sign is characterized by an increase in jugular venous pressure (JVP) during inspiration, which occurs due to impaired filling of the ventricles caused by a restrictive or constrictive process within the pericardial sac. In constrictive pericarditis, the thickened pericardium limits the heart's ability to expand properly during diastole, leading to this abnormal response during breathing.

In contrast, cardiac tamponade primarily presents with pulsus paradoxus, muffled heart sounds, and typically shows a different hemodynamic profile. The fluid accumulation in tamponade creates external pressure that affects heart function but does not lead to Kussmaul's sign. Instead, in cardiac tamponade, one might see a decrease in venous return during inspiration due to the pressure exerted by the fluid, leading to a different clinical manifestation.

Understanding these key differences helps to accurately differentiate between constrictive pericarditis and cardiac tamponade, especially in acute care settings where timely diagnosis is critical.