Compensatory Pause

Compensatory pause, an extended pause of the heart, continuing from a ventricular extrasystole until the next independent contraction. The cause of the compensatory pause is that following a ventricular extrasystole, a refractory period occurs, during which the ventricle cannot respond to the next impulse coming from the sinus; therefore, the nearest ventricular contraction after such an extrasystole occurs not in response to the first, but only to the second impulse from the sinus. If the heartbeats are so infrequent that the refractory period after the extrasystole manages to end before the next impulse from the sinus, then the compensatory pause may be absent. The compensatory pause can also be observed in extrasystolic allorhythmia-,. or 'parasystole' (Rothberger's), which occurs due to the simultaneous presence of two rhythms-normotopic and heterotopic (see Heart arrhythmias).