Relationship between the atrial-activation pattern around the triangle of Koch and successful ablation sites in slow-fast atrioventricular nodal reentrant tachycardia

Tomonori Watanabe; Hitoshi Hachiya; Hiroaki Watanabe; Kazunori Anno; Takafumi Okuyama; Tomohiko Harunari; Ayako Yokota; Masashi Kamioka; Takahiro Komori; Yuko Torigoe-Kurosu; Hisaki Makimoto; Tomoyuki Kabutoya; Yoshifumi Kimura; Yasushi Imai; Kazuomi Kario

doi:10.1002/joa3.12999

Relationship between the atrial-activation pattern around the triangle of Koch and successful ablation sites in slow-fast atrioventricular nodal reentrant tachycardia

J Arrhythm. 2024 Feb 9;40(2):363-373. doi: 10.1002/joa3.12999. eCollection 2024 Apr.

Authors

Affiliations

¹ Division of Cardiovascular Medicine Jichi Medical University School of Medicine Tochigi Japan.
² Cardiovascular Center, Tsuchiura Kyodo Hospital Ibaraki Japan.
³ Division of Cardiovascular Medicine, Shin-Oyama City Hospital Tochigi Japan.

Abstract

Background: The precise details of atrial activation around the triangle of Koch (ToK) remain unknown. We evaluated the relationship between the atrial-activation pattern around the ToK and success sites for slow-pathway (SP) modification ablation in slow-fast atrioventricular reentrant tachycardia (AVNRT).

Methods: Thirty patients with slow-fast AVNRT who underwent successful ablation were enrolled. Atrial activation around the ToK during sinus rhythm was investigated using ultra-high-density mapping pre-ablation. The relationships among features of atrial-activation pattern and success sites were examined.

Results: Of 30 patients (22 cryoablation; 8 radiofrequency ablation), 26 patients had a collision site of two wavefronts of delayed atrial activation within ToK, indicating a success site. The activation-search function of Lumipoint software, which highlights only atrial activation with a spatiotemporal consistency, showed non-highlighted area on the tricuspid-annulus side of ToK. In 23 of the patients, a spiky potential was recorded at that collision site outside the Lumipoint-highlighted area. Fifteen cryoablation patients with a success site coincident with a collision site outside the Lumipoint-highlighted area had significantly more frequent disappearances of SP after initial cryoablation (46.7% vs. 0%, p = .029), fewer cryoablations (3.7 ± 1.8 vs. 5.3 ± 1.3, p = .045), and shorter procedure times (170 ± 57 vs. 228 ± 91 min, p = .082) compared to the seven cryoablation patients without such sites. Four patients had transient AV block by ablation inside the Lumipoint-highlighted area with fractionated signals, but no patient developed permanent AV block or recurrence post-procedure (median follow-up: 375 days).

Conclusions: SP modification ablation at the collision site of atrial activation of the tricuspid-annulus side along with a spiky potential could provide a better outcome.

Keywords: catheter ablation; electro‐anatomical mapping; slow pathway modification.