Advantages and pitfalls of selective cardioneuroablation targeting the atrioventricular node

Swallowing syncope is a relatively rare reflex that mostly conditioned by pure cardioinhibitory response to swallowing and esophageal passage. Therefore, until recently, the predominant effective treatment method was permanent cardiac stimulation. With current availability of cardioneuroablation (CNA) for functional bradyarrhythmias, it logical consider also this option, especially in young patients. Although some patients may have subclinical intrinsic sinoatrial (SA) or atrioventricular (AV) node disorder only potentiated mechanism, most cases component predominant. Nevertheless, atropine testing highly desirable before CNA, thus verifying sufficient parasympathetic reserve, ideally documenting atropine-induced disappearance cardioinhibition due swallowing. In case report "Selective posteromedial left ganglionated plexus drug-resistant swallow with block" Yoneda colleagues [[1]Yoneda F. Shizuta S. Makiyama T. Masunaga N. Hoshida Kimura Selective block.Heart Rhythm Case Rep. 2023; (in press)PubMed Google Scholar], investigators correctly examined patient indicated very selective which subject commentary. The ECG phenotype corresponding – sinus arrest AV block decisive specific ablation strategy. If clinical manifestation arrest, not clear how would respond vagal irritation. such situation, both SA denervation reasonable choice, as hyperactivity frequently shared. standalone superior right (GP) (SRGP) has significant impact on node, complete nodal many achievable additional GP (PMLGP) [[2]Štiavnický P. Wichterle D. Jansová H. et al.Importance bilateral vagus nerve stimulation during [abstract].European Heart Journal. 2022; 43: 654https://doi.org/10.1093/eurheartj/ehac544.654Crossref PubMed Scholar]. SRGP alone can be clinically successful, even limited atrial aspect interatrial septum, we demonstrated previously [[3]Štiavnický Hrošová M. Kautzner J. Cardioneuroablation recurrent syncope.Europace. 2020; 22: 1741https://doi.org/10.1093/europace/euaa060Crossref Scopus (3) block, possible target PMLGP only. This approach advantages, but disadvantages. A advantage absence rhythm (SR) acceleration responsible postprocedural symptomatic tachycardia. Another shorter procedural radiofrequency time. disadvantage an increased risk incomplete and/or reinnervation node. Certainly, modulation significantly affected given dominant craniocaudal hierarchy innervation. endpoint loss balloon dilatation. Since intense at baseline, its strong indicator authors had used extracardiac (ECVS) [[4]Pachon M.J.C. Pachon M.E.I. Santillana P.T.G. al.Simplified effect evaluation electrophysiological procedures.JACC Clin Electrophysiol. 2015; 1: 451-460https://doi.org/10.1016/j.jacep.2015.06.008Crossref (55) Scholar] they might been surprised denervated after their lesion set. our series systematic use ECVS, achieved 40% (unpublished data). However, ECVS widely because dedicated neurostimulator commercially available. endocardial high-frequency (HFS) localize PMLGP. could repeat HFS ablated region, bring information about CNA effects, reported. known low sensitivity, specificity, reproducibility, so responses cannot considered reliable denervation. insufficient denervation, solution either further expand original cluster targeting ablate Marshall tract GP, affect and, same time, negligible strategy did result necessary SRGP. already associated unwanted SR acceleration. any case, achieving maximal ECVS-guided certainly goal. While does guarantee success occurs every patient, plausible speculate rather than higher rate late failure. Regardless these "technical" concerns, procedure although recurrence excluded since 11-month follow up fully cover period subsequent occur. pointed out episodes junctional were caused missing Figure 2 ("breakfast" ECG) shows swallowing, slowing instant from 82 72 bpm rapid return baseline occurred concomitant block. During similar subsidiary accelerated (Suppl. 2, "lunch" ECG). Theoretically, dynamics more prolonged pronounced pre-ablation hemodynamic deficit counterregulatory withdrawal baroreflex. After mechanism absent setting rhythm. Fortunately, described short asymptomatic. are commended educational important demonstrating again utility instead pacemaker implant treat performed avoid thereby excessive acceleration, like recently published [[5]Miranda-Arboleda A.F. Burak C. Abdollah Baranchuk A. Aksu Enriquez swallowing-induced syncope: To pace ablate, question.Heart https://doi.org/10.1016/j.hrcr.2023.01.013Abstract Full Text PDF (0) practice, principle selected bradyarrhythmias phenotype, whom perform followed gentle main entry partially modified moderate Such appropriate high resting considerable administration. Of course, „titration” purely empirical. interrelationship between rate, outcomes comprehensively investigated far. must always tailored individual should balance benefit risks. effort achieve perfect "overtreatment". context, keep mind processes considerably potent, effects remain irreversible. resigning ideal waiting possibility re-CNA sometimes At end, please allow terminological remark. Throughout text commentary, adhered nomenclature report. indeed merges almost indistinguishable anterior entire complex targeted right- left-atrial septum. unifying term "superior paraseptal GP" (SPSGP) seems appropriate. Similarly, "inferior (IPSGP) PMLGP, "left-sided" atrium proximal coronary sinus. proposed consensus document addresses methodology indication [[6]Brignole Calò L. al.Clinical controversy: indications https://doi.org/10.1093/europace/euad033Crossref blockHeartRhythm ReportsPreviewSwallow form neurally mediated (NMS), specifically type, It overactivation meals.1,2 Because efficacy adverse medications pacemakers,3,4 alternative therapeutic NMS, promising preliminary results. Full-Text Open Access