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Updated: May 31, 2026
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Published on: February 27, 2026
Recognition of inferiorly dislocated fast pathways guided by three-dimensional electro-anatomical mapping
Satoko Tanaka1, Akihiro Yoshida, Koji Fukuzawa
1Division of Cardiovascular Medicine, Department of Internal Medicine, Graduate School of Medicine, Kobe University, 7-5-1 Chuo-ku, Kusunoki-cho, Kobe, Hyogo, 650-0017, Japan.
Purpose:
Slow pathway (SP) ablation of atrioventricular (AV) nodal reentrant tachycardia (AVNRT) can be complicated by unexpected AV block even at sites >10 mm inferior to the bundle of His (HB), and one cause is thought to be the inferior dislocation of an antegrade fast pathway (A-FP). We assessed locations of FPs guided by CARTO.
Methods:
Sites of FPs were mapped guided by CARTO before SP ablation in 18 patients with slow-fast AVNRT. The A-FP was defined as the site with the minimum interval between the stimulus and HB potential when pace mapping in the right atrial septum.
Results:
The A-FP was 7.9 ± 7.5 mm inferior and 2.9 ± 5.0 mm posterior to the HB. In 6 of 18 patients (33%), the A-FP was inferiorly dislocated >10 mm to the HB. SP ablation was successfully performed in all patients at sites >10 mm from both the HB and the A-FP without AV block. In the inferiorly dislocated A-FP group, A-FPs seemed to be positioned much more on atrial sites and sufficiently posterior to SP ablation sites.
Conclusions:
The A-FP inferiorly dislocated >10 mm to the HB in one third of patients with AVNRT and seemed to be positioned deep on atrial sites. It is again emphasized that SP ablation within the triangle of Koch should be performed at a very ventricular annulus site, particularly in the inferiorly dislocated A-FP group.
