NBRC Registered Respiratory Therapist (RRT) Exit Practice Exam

Pulsus paradoxus is the exaggerated change in systolic blood pressure that occurs with the breathing cycle. During inspiration, intrathoracic pressure changes lead to reduced left-ventricular stroke volume in some conditions, causing a noticeable drop in systolic blood pressure (often more than 10 mmHg). This respiratory-related fluctuation is the hallmark, so describing a pulse or blood pressure that varies with respiration best captures the concept. The other options don’t fit: a constant pulse wouldn’t show the characteristic variation; an increased heart rate with inspiration describes respiratory sinus arrhythmia, not pulsus paradoxus; and pulsus paradoxus centers on systolic (not diastolic) pressure changes during inspiration.