What is pulses paradoxus?

Pulsus paradoxus is defined as a decrease in systolic blood pressure exceeding 10 mmHg during inspiration, typically accompanied by alterations in the pulse wave amplitude. This phenomenon is often observed in conditions such as cardiac tamponade, severe asthma, or other types of obstructive respiratory disease where the intrathoracic pressure changes significantly during the respiratory cycle.

During inspiration, negative intrathoracic pressure increases venous return to the right side of the heart, which can momentarily reduce left ventricular filling due to the decreased preload, leading to a drop in systolic blood pressure. Clinically, this drop can be detected as a change in the amplitude of the radial pulse, reflecting the diminished stroke volume during inspiration.

Understanding this phenomenon is crucial for healthcare providers, as it can indicate serious underlying conditions requiring immediate attention and management. The other options do not accurately describe this clinical sign; they either confuse the phasic changes associated with respiration or misrepresent the hemodynamic principles involved in pulsus paradoxus.