Pulsus paradoxus is defined as what?

• A. Exaggerated inspiratory increase in arterial pressure
• B. Exaggerated inspiratory decrease in arterial pressure (systolic and pulse pressure)
• C. Constant systolic pressure during inspiration
• D. Decrease in heart rate during inspiration

Answer: (B)

Pulsus paradoxus is an exaggerated fall in systolic arterial pressure during inspiration. Normally, inspiration causes a small dip in systolic BP due to intrathoracic pressure changes and how the heart fills, but in pulsus paradoxus the drop is greater than normal—typically more than about 10 mmHg—so both systolic pressure and pulse pressure decrease with inspiration. This sign appears in conditions like cardiac tamponade and certain severe lung diseases, where inspiratory mechanics markedly affect LV filling. It is not an inspiratory increase, nor a constant systolic pressure, nor a change in heart rate during inspiration.