Initial shortening of the tachycardia cycle length after the induction of fast-slow atrioventricular nodal reentrant tachycardia may support slow pathway as an antegrade limb of the reentry circuit

Catheter ablation of the slow pathway in patients with atrioventricular nodal reentrant tachycardia (AVNRT) is mainly performed using anatomical landmarks. We sought to see whether a new ablation catheter equipped with mini-electrodes may facilitate the mapping of slow pathway potentials for AVNRT ablation. We prospectively included patients referred for AVNRT in our center. Mapping and ablation were performed using an irrigated catheter equipped with 3 insulated mini-electrodes on the distal tip. Thirteen consecutive patients were included (85% female, median age 46 years). Slow pathway potentials could be identified in 77% of cases on mini-electrode bipolar tracings, versus 15% on conventional bipolar tracings (p = 0.0009). At the end of the procedure, double potentials on the ablation line were identified in all patients, only on mini-electrode bipolar tracings. Following ablation, an interval separating double potentials in sinus rhythm ≥15% of baseline tachycardia cycle length was associated with non-inducibility in all patients (p < 0.0001). No recurrence occurred during 1 year of follow-up. The use of mini-electrodes may help target slow pathway potentials during AVNRT ablation. Identification of sufficiently split double potentials on the ablation line might represent an electrophysiological endpoint in these patients.

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Superior-Type Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Phenotype Mimicking the Slow-Fast Type

Circulation Arrhythmia and Electrophysiology ◽

10.1161/circep.120.008732 ◽

2020 ◽

Vol 13 (11) ◽

Author(s):

Yoshiaki Kaneko ◽

Tadashi Nakajima ◽

Shuntaro Tamura ◽

Hiroshi Hasegawa ◽

Takashi Kobari ◽

...

Keyword(s):

Cycle Length ◽

Slow Pathway ◽

Atrioventricular Nodal Reentrant Tachycardia ◽

Reentrant Tachycardia ◽

Common Pathway ◽

His Bundle ◽

Overdrive Pacing ◽

Atrial Activation ◽

The Right ◽

Superior Type

Background: Superior-type fast-slow (sup-F/S-) atrioventricular nodal reentrant tachycardia (AVNRT) is a rare AVNRT variant using a superior slow pathway (SP) as the retrograde limb. Its intracardiac appearance, characterized by a short atrio-His (AH) interval and the earliest site of atrial activation in the His-bundle, is an initial indicator for making a diagnosis. Methods: Among 22 consecutive patients with sup-F/S-AVNRT, 3 (age, 68–81 years) patients had an apparent slow-fast (S/F-) AVNRT characterized by a long AH interval and the earliest site of atrial activation in or superior to the His-bundle region (tachy-long-AH). Results: The diagnosis of sup-F/S-AVNRT was based on the standard criteria in 2 patients and on the occurrence of Wenckebach-type atrioventricular block during tachycardia, which was attributable to a block at the lower common pathway (LCP) below the circuit of the AVNRT, detected owing to the lower common pathway potentials, in one patient. As with the typical S/F-AVNRT, tachy-long-AH was induced after a jump in the AH interval. In contrast to typical S/F-AVNRT, fluctuation in the ventriculoatrial interval was observed during the tachy-long-AH. Ventricular overdrive pacing was unable to entrain or terminate the tachy-long-AH. Moreover, the tachy-long-AH reciprocally transited to/from sup-F/S-AVNRT spontaneously or was triggered by ventricular contractions while the atrial cycle length and earliest site of atrial activation remained unchanged. Both tachycardias were cured by ablation at a single site in the right-side para-Hisian region of 2 patients and the noncoronary aortic cusp of one patient. Collectively, the essential circuit of both tachycardias was identical, and the tachy-long-AH was diagnosed as another phenotype of sup-F/S-AVNRT accompanied by sustained antegrade conduction via another bystander slow pathway breaking through the His-bundle owing to the repetitive antegrade block at the lower common pathway, thus representing a long AH interval during the ongoing sup-F/S-AVNRT. Conclusions: An unknown sup-F/S-AVNRT phenotype exists that apparently mimics the typical S/F-AVNRT and is also an unknown subtype of apparent S/F-AVNRT.

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Abstract 2647: Analysis of the Anatomical and Electrophysiological Characteristics of Tachycardia Circuit in Atrioventricular Nodal Reentrant Tachycardia Accompanied by the Block in the Upper Common Pathway

Circulation ◽

10.1161/circ.116.suppl_16.ii_586-c ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Kenji Morihisa ◽

Hiroshige Yamabe ◽

Yasuaki Tanaka ◽

Takashi Uemura ◽

Hisao Ogawa

Keyword(s):

Cycle Length ◽

Slow Pathway ◽

Atrioventricular Nodal Reentrant Tachycardia ◽

Reentrant Tachycardia ◽

Common Pathway ◽

Coronary Sinus Ostium ◽

Coupling Interval ◽

Atrial Electrogram ◽

Sinus Ostium ◽

Fast Pathway

We examined the anatomical and electrophysiological characteristic of the atrioventricular nodal reentrant tachycardia (AVNRT) accompanied by the ventriculo-atrial block during tachycardia, suggesting the presence of upper common pathway in 8 patients. Tachycardia was induced by the atrial burst and/or extrastimulation followed by the AH jump and the earliest atrial electrogram was observed at the His bundle (HB) site in all patients. The HA block was observed after gradual prolongation of the HA interval in 2 patient and abruptly in 6 patients. After administration of isoproterenol, 1:1 HA conduction was resumed in all patients. The tachycardia cycle length, AeHe interval and HeAe interval were 357±89, 275±55 and 80±44 msec, respectively. Single extrastimulus delivered from the HB site reset the tachycardia as soon as it was delivered during late diastole. However, single extrastimulus delivered from the inferior portion of the coronary sinus ostium (I-CSOS) was unable to reset the tachycardia without capturing the earliest atrial electrogram at the HB site, suggesting that atrium is not involved in the circuit. Thus, the longest coupling interval of single extrastimulus that reset the tachycardia at the HB site was significantly longer than that at I-CSOS (347±89 msec vs. 324±109 msec, p=0.012). The following return cycle after extrastimulation at the HB site did not differ from the tachycardia cycle length (357±89 msec, vs. 357±89 msec, p=NS), however, that at I-CSOS was significantly longer than the tachycardia cycle length (398±85 msec, vs. 357±89 msec, p=0.012). Catheter ablation was performed in a stepwise fashion starting at the inferior CSOS. Although the results of single extrastimulation showed that the atrial myocardium at I-CSOS was out of the reentry circuit, ablation near the I-CSOS, distant from HB site, selectively eliminated slow pathway conduction in all patients without impairment of fast pathway conduction. Conclusions: The AVNRT with upper common pathway has the characteristic of relatively long HA interval during tachycardia. Sub-atrial tissue, but not the atrium, extending from the HB site to I-CSOS forms the upper common pathway in AVNRT. It was shown that upper common pathway has an anatomical structure of a certain range.

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A Case Series of Very Slow Atrioventricular Nodal Reentrant Tachycardia Resembling Junctional Tachycardia

10.22541/au.164234606.66820132/v1 ◽

2022 ◽

Author(s):

Koji Higuchi ◽

Satoshi Higuchi ◽

Bryan Baranowski ◽

Oussama Wazni ◽

Melvin M. Scheinman ◽

...

Keyword(s):

Cycle Length ◽

Case Series ◽

Ventricular Rate ◽

Slow Pathway ◽

Atrioventricular Nodal Reentrant Tachycardia ◽

Reentrant Tachycardia ◽

Heart Rates ◽

Junctional Tachycardia ◽

Slow Pathway Ablation ◽

Atrioventricular Nodal Conduction

Introduction: The surface EKG of typical atrioventricular nodal reentrant tachycardia (AVNRT) shows simultaneous ventricular-atrial (RP) activation with pseudo R’ in V1 and typical heart rates ranging from 150-220/min. Slower rates are suspicious for junctional tachycardia (JT). However, occasionally we encounter typical AVNRT with slow ventricular rates. We describe a series of typical AVNRT cases with heart rates under 110/min. Methods: A total of 1972 patients with AVNRT who underwent slow pathway ablation were analyzed. Typical AVNRT was diagnosed when; 1) evidence of dual atrioventricular nodal conduction, 2) tachycardia initiation by atrial drive train with A-H-A response, 3) septal ventriculoatrial (VA) time < 70 ms, and 4) ventricular-atrial-ventricular (V-A-V) response to ventricular overdrive (VOD) pacing with post pacing interval-tachycardia cycle length (PPI-TCL) > 115ms. JT was excluded by either termination or advancement of tachycardia by atrial extrastimuli (AES) or atrial overdrive (AOD) pacing. Results: We found 11 patients (Age 20-78 years old, 6 female) who met the above-mentioned criteria. The TCL ranged from 560ms to 782ms. Except for one patient showing tachycardia termination, all patients demonstrated a V-A-V response and PPI-TCL over 115ms with VOD. AES or AOD pacing successfully excluded JT by either advancing the tachycardia in 10 patients or by tachycardia termination in one patient. Slow pathway was successfully ablated, and tachycardia was not inducible in all patients. Conclusions: This case series describes patients with typical AVNRT with slow ventricular rate (less than 110/min) who may mimic JT. We emphasize the importance of using pacing maneuvers to exclude JT.

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