Long RP Tachycardia and Short RP Tachycardia: Is the Nodoventricular Pathway a Culprit or an Innocent Bystander?

We encountered a single case in which a transition between orthodromic reciprocating tachycardia with a concealed nodoventricular pathway and atrioventricular nodal reentrant tachycardia with a bystander nodoventricular pathway was observed.

Approach to the Diagnosis and Management of Complex Fascicular Ventricular Tachycardias.

Complex ventricular tachycardias involving the fascicular system (fascicular ventricular tachycardias [FVTs]) can be challenging. In this review, we describe our approach to the diagnosis and ablation of these arrhythmias with 10 illustrative cases that involve (1) differentiation from supraventricular tachycardia; (2) assessment for atypical bundle branch reentry and other interfascicular FVTs; (3) examination of P1/P2 activation sequences in sinus rhythm, pacing, and tachycardia; and (4) entrainment techniques to establish the tachycardia mechanism and aid circuit localization. To summarize, 5 cases had prior ablation with 2 previously misdiagnosed as supraventricular tachycardia.

High-density electroanatomic mapping of atriofascicular pathways using multipolar mapping catheters can identify oblique pathways and avoid mechanical bump termination.

Background: Atriofascicular fibers (AFFs) are rare accessory pathways that have higher rates of recurrence after ablation because of either failure to identify AFF (M) potentials or mechanical termination with contact.

Objective: We aimed to evaluate whether electroanatomic mapping (EAM) using multielectrode, high-density nonlinear catheters can reliably localize AFF potentials and determine a site for ablation without causing mechanical termination.

Methods: Seven patients underwent electrophysiology studies (EPS) and EAM using high-density, multielectrode catheters for antidromic tachycardia using AFFs.