Pulsus Paradoxus
Normally SBP drops by less than 10mmHg in inspiration
Normally increased systemic venous return
In pathology if the potential pericardial space in reduced
Presence in exp - constant = drop
Causes
- pulmonary venous return reduced (blood pools in pulmonary vasculature)
- reduced preload to left heart
- reduced SBP
Normally increased systemic venous return
- usually extra space in pericardium
- free wall of right vent uses this space, minimal effect of left vent
In pathology if the potential pericardial space in reduced
- Right ventricle competes with left ventricle for space
Presence in exp - constant = drop
Causes
- Tamponade
- Pericarditis
- Asthma (hyperinflation compresses pericardium)
- Obstructive sleep apnoea (exaggerated neg pressure in inspiration)
- Tension pneumothorax (compresses pericardium)
- Pulmonary embolism
- Right ventricular myocardial infarction
- Bilateral pleural effusion (compresses pericardium)
- Restrictive cardiomyopathy
- Marked obesity
- Hypovolemic shock
- Pectus excavatum
- Extrinsic cardiac compression