Reverse pulsus paradoxus

Reverse pulsus paradoxus

Reverse pulsus paradoxus is an expiratory fall in pulse volume, the opposite of pulsus paradoxus. The classical causes of reverse pulsus paradoxus described are [1]:

1. Isorhythmic atrioventricular dissociation
2. Hypertrophic obstructive cardiomyopathy
3. Intermittent positive pressure ventilation in the presence of left ventricular failure

During intermittent positive pressure ventilation the swings in intrathoracic pressure is opposite to that of normal breathing. Hence the inspiratory blood pressure is higher than the expiratory blood pressure [2].

In case of isorhythmic AV dissociation, inspiratory increase in sinus rate results in sinus rhythm dominating over AV dissociation. In sinus rhythm there is AV synchrony and hence a higher pulse volume, compared to AV dyssynchrony in expiration.

In hypertrophic obstructive cardiomyopathy, the intensity of murmur decreases in inspiration due to decrease in obstruction. This is associated with an increase in arterial pressure and hence the reverse pulsus paradoxus [3].

References

1. Massumi RA, Mason DT, Vera Z, Zelis R, Otero J, Amsterdam EA. Reversed pulsus paradoxus. N Engl J Med. 1973 Dec 13;289(24):1272-5.
2. Wong FW. Pulsus paradoxus in ventilated and non-ventilated patients. Dynamics. 2007 Fall;18(3):16-8.
3. Brilakis ES, Nishimura RA. Dynamic respiratory changes in hypertrophic cardiomyopathy. Heart. 2004 Mar;90(3):296.