What is meant by pulses paradoxus in clinical terms?

Pulsus paradoxus refers to an abnormal decrease in stroke volume during inspiration, leading to a noticeable drop in blood pressure. This phenomenon is typically associated with conditions like cardiac tamponade, severe asthma, or other forms of respiratory distress where intrathoracic pressure changes significantly during the respiratory cycle.

During normal breathing, blood pressure may slightly fluctuate, but a decrease of more than 10 mmHg during inspiration signifies a pathological state. The physiological explanation involves the augmented venous return to the right side of the heart during inspiration, which can reduce left ventricular filling if there is a constraint on the heart, hence decreasing stroke volume and blood pressure. Understanding this concept is critical for recognizing and managing conditions that manifest with pulsus paradoxus in clinical settings.