aetiology

Last reviewed 01/2018

The causes of pulsus paradoxus include:

• obstructive airways disease:
• during inspiration, the lower intrathoracic pressure favours the venous filling of the right ventricle more than the left
• the relative overfilling of the right ventricle may compromise the lumen of the left ventricle resulting in a lower stroke volume and lower systolic pressure

• pericardial tamponade:
• increased intra-pericardial pressure during inspiration results in a compensatory increase in central venous pressure (Kussmaul's sign)
• on the left side of the heart there is insufficient pressure to maintain the filling of the left ventricle: a low stroke volume results in a low systolic pressure