Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr;63(3):573-580.
doi: 10.1007/s10840-021-01061-4. Epub 2021 Sep 13.

Physiology of slow pathway conduction during sinus rhythm: evidence from high density mapping within the triangle of Koch

Steven J Bailin  1 , Troy E Rhodes  1 , J Chapman Arter  2 , Cyrus Kocherla  1 , Nayanjyoti Kaushik  3
Affiliations

Physiology of slow pathway conduction during sinus rhythm: evidence from high density mapping within the triangle of Koch

Steven J Bailin et al. J Interv Card Electrophysiol. 2022 Apr.

Abstract

Purpose: To evaluate nature of AV nodal activation in patients with AVNRT using high density electro-anatomic mapping (HD-EAM).

Methods: HD-EAM was created in 30 patients with AVNRT from the triangle of Koch (ToK) in sinus rhythm (SR). Isochronal late activation maps (ILAM) were created. EAMs were analyzed for slow pathway (SPW) and fast pathway (FPW) activation. A pivot point (PP) was defined where FPW and SPW collided and pivoted back to the AV node (AVN). Conduction was assessed with programmed extrastimulus (PES) in 9 patients until FPW refractory period (ERP). The change in PP distance from the HIS (ΔPP) was measured in SR and PES. The ΔPP was compared to ΔAH. The PP was ablated and SR re-mapped.

Results: The FPW activates the His and moves inferiorly toward the coronary sinus (CS). Activation also enters the ToK near the CS and collides with the FPW which then pivots around a functional line of block (LOB) within the ToK and moves superiorly along the septal tricuspid annulus. PP electrograms are fractionated, low amplitude, and consistent with SPW potentials (Haissaguerre et al. in Circulation 85:2162-2175, 1992). During PES the PP moved superiorly until FPW ERP when only SPW activation occurs. Normalized ΔAH and ΔPR vs ΔPP was highly correlated p < 0.0001. Ablation at the PP was successful and associated with loss of SPW fusion and pivot.

Conclusion: We conclude HD-EAM/ILAM provide a novel method for localizing the SPW in SR. This study provides further understanding of dual AV nodal physiology and may aid in targeting the SPW for ablation of AVNRT.

Keywords: 3D electroanatomic mapping; AV nodal activation; AVNRT; Slow pathway ablation.

PubMed Disclaimer

References

    1. Bailin SJ, Korthas MA, Weers NJ, Hoffman CJ. Direct visualization of the slow pathway using voltage gradient mapping: a novel approach for successful ablation of atrioventricular nodal reentry tachycardia. EP Europace. 2011;13(8):1188–94. https://doi.org/10.1093/europace/eur112 . - DOI
    1. Acute and long-term outcome of cryoablation therapy of typical atrioventricular nodal reentrant tachycardia Hamid Bastani*, Jonas Schwieler, Per Insulander, Fariborz Tabrizi, Frieder Braunschweig, Go¨ ran Kenneba¨ck, Nikola Drca, Bita Sadigh, and Mats Jensen-Urstad Department of Cardiology at the Karolinska Institute, Karolinska University Hospital, S-141 86 Stockholm, Sweden Received 15 March 2009; accepted after revision 10 June 2009; online publish-ahead-of-print 4 July 2009.
    1. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2016;133:e506–74. - PubMed
    1. Park JS, Hwang H, Joung B, et al. Clinical and electrophysiologic characteristics before and after radiofrequency ablation of sustained slow atrioventricular nodal pathway conduction. JACC Clin Electrophysiol. 2016;2:367–74. - DOI
    1. Chua K, et al. High-resolution mapping of the triangle of Koch: spatial heterogeneity of fast pathway atrionodal connections. Heart Rhythm. 2018;15.3:421–9. - DOI

LinkOut - more resources