SEARCH RESULTS FOR: Pulsus-Paradoxus

Pulsus Paradoxus

Pulsus Paradoxus: Pathogenesis and Clinical Findings Inspiration: Diaphragm and intercostal muscles contract Author: Yan Yu, Victória Silva, Layla Al-Yasiri Reviewers: Sean Spence, Laura Craig, Juliette Hall, Raafi Ali, George Tadros. Shahab Marzoughi Nanette Alvarez* * MD at time of publication Vascular pathology (rare) Thoracic cavity expands Lungs expand and intrathoracic pressure ↓ Physiologic: ↑ Venous return to right (R) heart ↑ R heart preload (volume of blood inside the ventricle right before it contracts) ↑ Blood pools in the right side of the heart Obstructive lung diseases (e.g., COPD**, asthma**) Hyperinflated lungs ↑ Stretching of pulmonary vessels at rest On inspiration, ↑↑ stretching of pulmonary vessels ↑↑ Blood pools within pulmonary vasculature ↓↓ Flow to L heart Pathologic: Constrictive pathologies (e.g., cardiac tamponade**, constrictive pericarditis**) Decreased pericardial compliance Constriction of ventricles On inspiration, ↑ venous return to R heart (normal) R ventricle unable to fully expand due to ↓ compliance Septum bows into L ventricle L ventricle unable to fully expand ↓↓ Filling of L heart ↓↓ L ventricular end diastolic volume ↓↓ L heart stroke volume ↓↓ Cardiac output Pulsus Paradoxus Exaggerated ↓in systolic BP on inspiration (>10mmHg) Air flows into the lungs Pulmonary vessels are physically stretched/pulled ↑ Blood pools in pulmonary vessels ↓ Return of blood to left (L) heart ↓ L heart preload ↓ L heart stroke volume ↓ Cardiac output Obstruction of superior or inferior vena cava (e.g., clot) ↓↓ Venous return to R heart at rest ↓↓ Right heart filling ↓↓ Blood flow to pulmonary arteries Pulmonary embolism** Clot occludes pulmonary arteries/ arterioles ↓↓ Flow to pulmonary veins At rest, ↓↓ flow to L heart On inspiration, ↓↓↓ flow to L heart ↓ Systolic blood pressure (BP) of < 10mmHg on inspiration BP = cardiac output x systemic vascular resistance **See corresponding Calgary Guide slides Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published Jan 21, 2013; updated Dec 3, 2024 on www.thecalgaryguide.com