Two Accessory Pathways, Dual AV Nodal Conduction, and 1:2 Ventriculoatrial Conduction in a Patient with Multiple Supraventricular Tachycardias

Abstract

Multiple supraventricular tachycardias were induced in a patient with two left posterior accessory pathways and dual atrioventricular nodal conduction. One of the accessory pathways conducts slowly and exhibits decremental conduction. A "double retrograde response" (2:1 ventriculoatrial conduction) due to simultaneous retrograde propagation of a single ventricular depolarization over two longitudinally dissociated pathways plays a role not only in tachycardia initiation, but in the maintenance of a unique, irregular tachycardia.