What is pulsus paradoxus and what cardiac condition does it indicate?

Pulsus paradoxus is characterized by a drop in systolic blood pressure of more than 10 mmHg during inspiration. This phenomenon can be indicative of several pathological states, most notably cardiac tamponade. In this condition, the heart is encased in fluid, which limits its ability to fill adequately during diastole; therefore, when a person inhales, the intrathoracic pressure decreases, leading to increased venous return and exaggerated ventricular filling. This diminished stroke volume during inhalation results in a drop in blood pressure that is manifest as pulsus paradoxus.

The relationship between pulsus paradoxus and cardiac tamponade is particularly critical because it serves as a clinical sign that can guide healthcare professionals in diagnosing and managing serious cardiovascular issues. Recognizing the presence of pulsus paradoxus can prompt further investigation into the underlying causes, such as pericardial effusion or constrictive pericarditis, conditions that may compromise hemodynamic stability and require medical intervention.