Selective right atrial cardioneuroablation in functional atrioventricular block

We read the article with a great interest by Rivorola et al.¹ published recently in Europace Journal entitled ‘Selective atrial vagal denervation guided by spectral mapping to treat advanced atrioventricular block’. In this case report, the authors have reported the consequence of cardioneuroablation procedure in a 38-year-old male with vagally mediated atrioventricular (AV) block during sleep. They targeted the endocardial regions with spectral characteristics of endocardial vagal innervation via a complete spectral mapping of the right and left inter-atrial septum topography.

It is well known that three main parasympathetic ganglia (Ganglion A–C), which were located outside the atrial wall in para-cardiac fat pads, provide to innervation of the heart.² The fibres for vagal innervation of AV node go via the crux area of heart. As it was shown by Armour et al.,³ the largest number of ganglia (an average of 194 of the 458 per heart) is located on the posterior surface of the right atrium (RA) adjacent to the inter-atrial groove (Ganglion C), and this ganglion contains much more neurons than in other ganglia.

On the basis of these anatomical relationship, it seems reasonable that selective vagal denervation of AV node may be achieved by endocardial ablation through the RA in the patients with functional AV block. This approach was firstly presented by our group in a patient with permanent functional AV block.⁴ In our recently published study, selective right atrial approach was successful in six of seven patients with functional AV block.⁵ Four of the seven patients with functional AV block were admitted to our clinic with intermittent high-degree AV block and recurrent syncope. Electrocardiogram on admission was normal in these patients. The other three patients in this group were referred to our clinic to implant permanent pacemaker for symptomatic permanent 2:1 AV block with recurrent syncope. In these patients, the mean number of RF lesions was 23.8 ± 2.6.

We speculated that potential complication due to trans-septal puncture may be eliminated by selective right atrial approach with similar success ratio.

References