Accessory pathway potential recording in a case of permanent junctional reciprocating tachycardia with decremental conduction localized on the atrial site.

Permanent junctional reciprocating tachycardia (PJRT) is an uncommon form of atrioventricular reentrant tachycardia due to the presence of an accessory pathway characterized by slow and decremental retrograde conduction. We report a case of PJRT where we demonstrated the possibility of recording a distinct accessory pathway potential. Decremental retrograde conduction was evident using ventricular extrastimuli and it was also adenosine-sensitive. Delivering ventricular extrastimuli a prolongation of the accessory pathway potential-atrium interval was seen demonstrating that decremental conduction was located at the atrial insertion of the pathway. The accessory pathway was successfully ablated using the potential as the target of radiofrequency delivery. These electrophysiological findings seem to support the hypothesis that a nodal-like structure may be responsible for this arrhythmia.