A patient with ventricular extrasystoles is reported in whom Type A alternating Wenckebach periodicity in the re-entrant path of the extrasystoles is suggested for the first time. Namely, it appears that 2:1 exit block occurs at a proximal level in the re-entrant path and block of the Wenckebach form occurs at a distal level in the path. The presence of three-level block in the re-entrant path is also suggested in this patient.