The parasystole, a limitation of sinus node recovery time estimation.

ABSTRACT

Sinus node recovery time, used as an objective parameter of the sinus node function estimation, may be left out in the situation in which an atrial parasystolic focus is present. The overdrive suppression induced through rapid atrial pacing is without effect upon the protected parasystolic focus, and its firing will disturb the post-drive pause. This situation is noticed in two instances and demonstrated in one case.