[Junctional reciprocating tachycardia with second degree A-V block (author's transl)].

Two cases of paroxysmal supraventricular tachycardia sustained by an atrioventricular junctional reentry mechanism are presented. During the electrophysiological study it was possible to induce paroxysms of tachycardia showing 3:2 Lucianai-Wenckebach type and 2:1 atrioventricular block. The site of the block, its functional nature and the possible involvement of an anterogradely blocked atrio-nodal or atrio-His accessory pathway in the reentry circuit are discussed.