Acute effects of cardioneuroablation on ventricular arrhythmia inducibility and refractoriness in patients with functional bradyarrhythmias
A Sikorska, M Niedzwiedz, A Nowinski, T Krynski, A Gwalkiewicz-Mazanska, J Baran, R Piotrowski, P KulakowskiAbstract
Background
Cardioneuroablation (CNA) is more and more widely used to treat functional bradyarrhythmias. Because the procedure reduces parasympathetic drive to the heart, concerns have been raised regarding its safety, particularly possible proarrhythmic effects.
Purpose
To assess acute effects of CNA-induced total vagal denervation, measured by extracardiac vagal stimulation (ECVS), on ventricular refractoriness and vulnerability to ventricular arrhythmias.
Methods
This prospective Roman 4 study (NCT06458140) included 80 patients (51 (63,8%) females, mean age 42±14, range 18-71 years) with vasovagal syncope (N=56), functional atrioventricular block (N=11) or functional bradycardia (N=13) who underwent electro-anatomical- and intracardiac echocardiography-guided CNA using ECVS as intraprocedural endpoint. Vulnerability to complex ventricular arrhythmias was assessed using programmed ventricular stimulation (PVS; up to three extrastimuli). PVS was performed and right ventricular effective refractory period (VERP), ventricular action potential duration (VAPD), corrected QT interval (QTc), as well as QT dispersion (QTd) were measured at four time points: at baseline (B), after CNA (C), after CNA and atropine (2 mg) (C+A), and after CNA, atropine and isoproterenol (20 µg) (C+A+I).
Results
Results are summarized in the table. Ventricular tachycardia was induced in 2 patients (one at baseline and one after CNA). Both patients had pre-existing cardiac conditions (history of Takotsubo syndrome with syncope and prior infective endocarditis requiring pacemaker removal). VAPD was significantly shortened after CNA, whereas changes in VERP were nonsignificant (except after isoproterenol). CNA combined with atropine and isoproterenol caused significant QTc prolongation by Bazett’s formula whereas using Fredericia’s formula prolongation occurred only after atropine and isoproterenol. QTd remained unchanged across all assessments.
Conclusions
CNA changes several ventricular electrophysiological parameters, however, acute inducibility of complex ventricular arrhythmias is very rare, even during complete parasympathetic denervation (C+A) with additional adrenergic stimulation (C+A+I), and seems to be associated with the presence of underlying cardiovascular disease. Whether these changes persist over long-term follow-up, during which partial reinnervation typically occurs, and whether CNA may occur proarrhythmic in patients who later develop cardiac disorders, is unknown.Table