Po-03-032 selective denervation of atrioventricular node during cardioneuroablation: an impact of standalone targeting the posteromedial left ganglionated plexus

Radiofrequency (RF) catheter ablation of anterior right ganglionated plexus (ARGP) is effectively used for sinus nodal denervation but it has also an impact on vagal modulation of the atrioventricular node (AVN). Ablation of the posteromedial left ganglionated plexus (PMLGP) is critical for the elimination of vagal input to the AVN. For the treatment of symptomatic functional AV block, the ARGP followed by PMLGP ablation is the usual ablation strategy. We investigated the effects of an inverted (i.e., PMLGP followed by ARGP) ablation strategy. The study included 19 patients with functional bradyarrhythmias (age: 42 ± 12 years, 79% males) who underwent cardioneuroablation in general anesthesia. PMLGP was ablated from [1] the left atrium (LA) aspect - middle bottom part adjacent to the inferior rim of fossa ovalis, [2] the coronary sinus (CS) - proximal 2-cm segment, and [3] the right atrium (RA) aspect - between the fossa ovalis and inferior vena cava. A total of 90 seconds of RF energy was delivered to each of the ablation sites. The response to extracardiac vagus nerve stimulation (ECVS; 50 Hz, 0.05 ms, 1 V/kg [<70V], 5 s) while atrial pacing (100 bpm) was recorded at baseline and after each ablation step. The longest R-R interval during the ECVS was considered a measure of AVN denervation. The right and left vagus nerves were sequentially stimulated, and the stronger response of the AVN was considered representative. Temporal development of outcome measure with the progression of PMLGP ablation is shown in the Figure. In 11 patients, standalone PMLGP ablation resulted in complete AVN denervation (Figure, left panel). In 8 patients, the AVN still responded to ECVS after PMLGP ablation (Figure, right panel). Complete AVN denervation was reached in 5 of 8 patients by subsequent standard ARGP ablation. In the remaining 3 patients, ablation of superior left ganglionated plexus (n=3) and extension of PMLGP ablation (n=2) was performed to achieve a complete AVN denervation. PMLGP ablation alone was able to denervate the AVN in 11 of 19 patients. This observation may have practical value in patients with symptomatic episodes of AV block. Targeting PMLGP only could prevent the unnecessary acceleration of sinus node in selected patients. The durability of AVN denervation when using this ablation strategy remains to be investigated.