Atypical Slow-Slow Atrioventricular Nodal Reentrant Tachycardia with Use of a Superior Slow Pathway

Abstract

We report a case of atypical slow-slow atrioventricular nodal reentrant tachycardia (AVNRT) utilizing a superior slow pathway as a retrograde limb. The standard electrophysiological criteria confirm the diagnosis of this AVNRT by successfully excluding a diagnosis of atrial tachycardia and atrioventricular reentrant tachycardia. The earliest atrial activation during tachycardia was found at the interatrial septum 17.5 mm superior to the site identified during retrograde conduction with the fast pathway. The tachycardia was not inducible after ablation at the right posterior septum, consistent with successful ablation of the typical slow pathway.

Fast–slow atrioventricular nodal re‐entrant tachycardia incorporating superior and inferolateral left atrial slow pathways

“…Fast-slow AVNRT using an SSP is known to usually have a short AH interval, but in this case, since the AH and HA intervals during the tachycardia were nearly identical, a typical long RP pattern was not observed. Kaneko et al 7,8 have reported that not all cases of AVNRT via an SSP necessarily exhibit a short AH and long RP pattern, suggesting that there may be interindividual diversity in the electrocardiographic appearance, probably due to a balance between the antegrade and retrograde conductivities during the tachycardia. They also reported that a double atrial response characterized by two types of retrograde conduction near the superior region of the AV node 4 is recognized in some cases, but it was not observed in this case.…”

Fast-slow Atrioventricular Nodal Reentrant Tachycardia Incorporating Superior and Inferolateral Left Atrial Slow Pathways

“…Fast-slow AVNRT using an SSP is known to usually have a short AH interval, but in this case, since the AH and HA intervals during the tachycardia were nearly identical, a typical long RP pattern was not observed. Kaneko et al have reported that not all cases of AVNRT via an SSP necessarily exhibit a short AH and long RP pattern, suggesting that there may be inter-individual diversity in the electrocardiographic appearance probably due to a balance between the antegrade and retrograde conductivities during the tachycardia 7,8 . They also reported that a double atrial response characterized by two types of retrograde conduction near the superior region of the AV node 4 is recognized in some cases, but it was not observed in this case.…”

A Novel Concept in AVNRT

“…Kaneko, et al presented a case of atypical slow-slow AVNRT with a reentrant circuit between the antegrade slow pathway over the right inferior extension and retrograde superior slow pathway. 7) This case demonstrated that an ablation strategy targeting the antegrade slow pathway around the right inferior septum could be the optimal approach for atypical slow-superior slow AVNRT, particularly since this strategy is already established.…”