Pulsus paradoxus represents – Correct answer: a) Exaggerated inspiratory fall in blood pressure
Normally there is an inspiratory fall in blood pressure of less than 10 mm Hg. This fall is exaggerated in pulsus paradoxus and can be noted in cardiac tamponade and severe obstructive pulmonary disease. In cardiac tamponade, right heart compression prevents inspiratory increase in flow to the right heart and exaggerates the usual drop in venous return to the left heart resulting in fall of blood pressure. In chronic obstructive pulmonary disease, the swings in venous return occur due to the wide swings in intrathoracic pressure.
If it is an exaggeration of the normal response, what is the ‘paradox’ in pulsus paradoxus? The term was introduced when it was noted that pulse was absent in inspiration in spite of audible heart sounds in cases of severe pulsus paradoxus (pulsus paradoxus totalis).