A drop in systolic pressure that coincides with expiration rather than inspiration. This is typical of
HOCM (hypertrophic obstructive cardiomyopathy), where the ventricle is too stiff to adequately fill. It also
can be seen in patients with left ventricular failure who are on positive pressure ventilation (PPV). In this case, PPV displaces the wall of the ventricle inward during systole, thus assisting ventricular emptying and causing a slight rise in systolic pressure during mechanical inspiration. Note that a reversed pulsus paradoxus in ventilated patients is a sensitive indicator of hypovolemia. Finally, a reversed pulsus paradoxus can
also be seen in patients with isorhythmic dissociation. The atrial activity precedes the ventricular activity
during inspiration, and follows it during expiration. The atrial contribution during inspiration increases stroke
volume, while the lack of it during exhalation decreases it.
HOCM (hypertrophic obstructive cardiomyopathy), where the ventricle is too stiff to adequately fill. It also
can be seen in patients with left ventricular failure who are on positive pressure ventilation (PPV). In this case, PPV displaces the wall of the ventricle inward during systole, thus assisting ventricular emptying and causing a slight rise in systolic pressure during mechanical inspiration. Note that a reversed pulsus paradoxus in ventilated patients is a sensitive indicator of hypovolemia. Finally, a reversed pulsus paradoxus can
also be seen in patients with isorhythmic dissociation. The atrial activity precedes the ventricular activity
during inspiration, and follows it during expiration. The atrial contribution during inspiration increases stroke
volume, while the lack of it during exhalation decreases it.