Absence of transseptal access reduces the efficacy of cardioneuroablation

Background/Introduction Cardioneuroablation (CNA) reduces excessive vagal influence on the sinoatrial (SAN) and atrioventricular (AVN) nodes. The effect of right atrial versus biatrial CNA was investigated separately for superior and inferior paraseptal ganglionated plexi (SPSGP and IPSGP) under strict procedural standards. Such a stringent study was not performed for CNA that simultaneously targets SPSGP and IPSGP. Purpose To investigate (1) the efficacy of SPSGP and IPSGP ablation performed using a non-transseptal approach (primary ablation), and (2) the additive value of complementary left atrial (LA) ablation after obtaining transseptal access. Methods Thirty patients (15 men, 43 ± 12 years) with recurrent cardioinhibitory syncope or symptomatic functional bradyarrhythmia underwent standardized CNA with radiofrequency lesions guided by the ablation index: 450 in atria and 350 in the coronary sinus (CS). The primary lesion set included right-sided SPSGP ablation (4 lesions) and IPSGP ablation from the right atrial (RA) and CS aspects (3 lesions each). The complementary lesion set from the aspect of LA targeted SPSGP (4 lesions) and IPSGP (3 lesions). The impact of CNA on vagal modulation of SAN and AVN was assessed by maximal P–P and R–R intervals inducible by extracardiac vagal stimulation (ECVS) via right (R-ECVS) and left jugular vein (L-ECVS). Results The sinus rate increased significantly after primary ablation (from 61 ± 12 to 74 ± 14 bpm, P < 0.005) and further increased after complementary LA ablation (from 74 ± 14 to 80 ± 15 bpm, P = 0.005). Both R-ECVS and L-ECVS showed significant shortening of P–P and R–R intervals after primary ablation, which significantly progressed after complementary LA ablation (Figure 1). The additive value of complementary LA ablation was more noticeable in the case of AVN nodal vagal modulation. Conclusion(s) Although non-transseptal CNA substantially attenuates vagal modulation of the SAN and AVN, complementary LA CNA significantly contributes to further denervation of both nodes. Biatrial CNA should be considered the therapeutic standard.