Persistent VA dissociation during atrioventricular nodal reentry tachycardia: The existence of upper common pathway

Abstract

The existence of the upper common pathways is not well‐established yet. This case describes atrioventricular nodal reentry tachycardia with persistent ventriculoatrial dissociation that proof of upper common pathway existence.

An uncommon response to a His refractory premature ventricular complex during a short RP supraventricular tachycardia: What is the mechanism?

“…The tachycardia with a short septal VA interval of <70 ms excludes ORT, although septal AT with a prolonged AV conduction is possible . The His‐refractory VPC stopped the tachycardia without changing the retrograde atrial activation sequence (RAAS) and AA interval, which excludes the diagnosis of AT and JT, leaving us the possibility of NFRT or AVNRT with bystander NF pathway . Whereas a His‐refractory VPC terminates the tachycardia without conducting to the atrium, it should not have any effect on the ongoing tachycardia during AVNRT.…”

The ongoing mystery of the atrioventricular node

“…In this issue of PACE, Iqbal et al. present an interesting case in support of the “Believers”—a young man with AVNRT manifesting both persistent AV dissociation and transient AV block . Nodofascicular reentrant tachycardia with AV dissociation was excluded by the presence of AV block.…”

Electrophysiological maneuvers for concealed nodofascicular or upper common pathways: Positive findings always work, but negative findings does not

“…We read with great interest the article by Iqbal et al and the accompanying editorial by Ho confirms the debate about the existence of upper common pathways (UCP) and lower common pathways (LCP) . We want to address some points that merit more attention and would like to hear the author's opinions about the differentiating role of some electrophysiological maneuvers between the atrioventricular (AV) nodal reentrant tachycardia (AVNRT) with UCP block and the concealed nodofascicular (NF) or nodoventricular (NV) reentrant tachycardia (NFRT and NVRT, respectively).…”

“…As summarized in the editorial, some discriminating electrophysiological features and pacing maneuvers have been reported in literature to support or refute the UCP/LCP concept . Factors favoring NFRT versus AVNRT with UCP block include changes in tachycardia cycle length (CL) with the development of bundle brunch block (BBB), advancement of the next His with a ventricular premature depolarization (VPD) delivered when the His is refractory, and tachycardia resetting or termination with a VPD when the His bundle is refractory or with late coupled VPD . Persistence of the tachycardia despite ventriculoatrial (VA) block rules out atrial tachycardia and atrioventricular reentrant tachycardia as the mechanism and excludes the atria as a part of the circuit.…”

“…Persistence of the tachycardia despite ventriculoatrial (VA) block rules out atrial tachycardia and atrioventricular reentrant tachycardia as the mechanism and excludes the atria as a part of the circuit. This leaves only AVNRT with UCP block and the much less commonly observed NV/NFRT …”