gap phenomenon

gap phe·nom·e·non

a short period in the cycle of the atrioventricular or intraventricular conduction allowing passage of an impulse which at other times would be blocked in transit.
Synonym(s): excitable gap

gap phe·nom·e·non

(gap fĕ-nom'ĕ-non)
A short period in the cycle of the atrioventricular or intraventricular conduction allowing passage of an impulse that at other times would be blocked in transit.