Author's Reply-Ablation for atrioventricular block.

We would like to thank Aksu and colleagues for their contribution to the field of cardioneuroablation, which we carefully follow. Naturally, we are aware of their case report presented in 2015. However, even Aksu’s group was not the first to report on a functional atrioventricular (AV) block treated with cardioneuroablation instead of pacemaker implantation. That aside, a detailed look at the case reports presented by Aksu’s group and ours reveals significant differences. Aksu reported on a 54-year-old woman, with a recent history of dizziness and syncope, who was referred to their clinic for pacemaker implantation. Unlike our case report, a slow pathway (SP) ablation had been carried out uneventfully 3 years before the onset of symptoms, suggesting that functional impairment of AV node conduction properties occurred much later and was most likely not associated with the SP ablation at all. In our case report, however, a 2:1 AV block developed immediately after SP ablation, and our patient, who was 19 years old, refused to undergo pacemaker implantation. Only because the iatrogenic impairment, caused by the SP ablation, was not overly extensive were we able to obtain a favorable result using cardioneuroablation. In short, eliminating vagal inputs to the AV node allowed the prevailing sympathetic tone affecting the AV node to reconstitute normal conduction. Lastly, we would also like to point out the different ablation approach used in our case, ie, extracardiac vagal stimulation. We meticulously targeted only the parasympathetic innervation of the AV node and took great pain to avoid ablating fibers innervating the sinoatrial node; as such, we avoided a potential increase in heart rate after cardioneuroablation, which might have been unpleasant for the patient. Extracardiac vagal stimulation allowed us to carry out this procedure using a carefully titrated, step-wise approach.