It is a term used to describe a patient with isorhythmic dissociation from complete heart block who was misdiagnosed as having pulsus paradoxus. This was in reality due to increased sinus rate from inspiration, which temporarily positioned the P waves in front of the QRS, thus synchronizing (and maximizing) atrioventricular contraction. The misdiagnosis can be avoided by strictly adhering to the guidelines for pulsus paradoxus laid down by Gauchat and Katz:
The pulse must be felt in all the accessible arteries.
There is no need for deep inspiration.
There must be no irregularity of cardiac action.
The pulse must be felt in all the accessible arteries.
There is no need for deep inspiration.
There must be no irregularity of cardiac action.