CONGRESS ABSTRACT

Background: Cardioneuroablation is conceivable for functional bradyarrhythmias caused by a dysregulation of the autonomic nervous system. Cardioneuroablation is an ablation technique that targets epicardial ganglionic plexi to reduce syncope burden and avoid pacemaker implantation in patients with vasovagal syncope and functional forms of sinus node dysfunction and atrioventricular block. The ergometric test and the atropine test are useful for differentiating intrinsic from extrinsic bradyarrhythmias, fundamental distinctions before considering subjecting a patient to the CNA procedure. Zanubrutinib is a Bruton’s tyrosine kinase inhibitor. Although heart block is not known as its side effect, there is some evidence that this drug could create second-degree heart block. Case summary: In this study, we report the case of a 68-year-old woman affected by non-Hodgkin lymphoma treated with Zanubrutinib. The patient comes to our attention for the finding of atrioventricular conduction disorders (AV block 1st degree, AV block 2nd degree Mobitz I (Wenckebach) and AV block 2nd degree 2:1). During hospitalization she performed echocardiogram and treadmill stress test. During effort, evidence of progressive increase in heart rate and reduction of the PQ interval. During the electrophysiological study, evidence, after infusion of atropine (0.02 mg/kg/ev), of improvement of the Wencheback point (from 408 to 320 ms). Using the CARTO mapping system, neuromodulation procedure of the atrioventricular node ganglion is performed. Procedure: the procedure was performed with a QDOT ablation electrocatheter by delivering radiofrequency at the infero-posterior wall of the coronary sinus ostium with an ablation index of 440 and, specularly, to the previous lesion at the infero-septal mitral ridge with an ablation index of 600. During ablation, evidence of irritative rhythm starting from the coronary sinus ostium. At the end of the procedure, minimal shortening of the PQ was noted. Results: the patient continued telemetric monitoring and performed 24-hour Holter ECG without evidence of atrioventricular blocks. Conclusions: Although not yet included in current guidelines, the CNA procedure could be used to treat AV node dysfunction in young subjects. However, more randomized studies are needed. In this particular case, neuromodulation was useful in the management of atrioventricular blocks in a patient, allowing us to continue antineoplastic therapy.