Table 3.

Practical advice for performing CNA

General

•Almost all anesthetic agents commonly used will impact the autonomic nervous system, but adequate controlled sedation with bispectral index between 40 and 50 will minimize significant impact on CNA for mapping and assessing procedural endpoints. •Conscious sedation is also acceptable and preferred if tolerated because of its minimal direct effects on the vagal response.

•Atropine or any drug with autonomic action can prevent the correct assessment of denervation during CNA. These medications should not be used during anesthesia and in the days preceding the CNA.

•Ablation with an irrigated-tip catheter, 30 W, 42°C, 30–60 s per site

Identification of ablation sites and procedural endpoint

•Anatomical ablation can be impaired by individual differences and by changes in the position and rotation of the heart.

•If denervation is not achieved with anatomical CNA, the expansion of the ablation to additional AF sites is done using different mapping techniques.∗ •In addition to ablation of areas thought related to the 4 major GPs, ablation of the roof of the coronary sinus and of Waterston's groove may be considered in refractory cases.

•Confirmation of successful denervation by using vagal stimulation

Special considerations for AV node denervation

•AV node denervation is significantly more difficult than sinus node denervation. The complexity of AV node innervation demands higher accuracy of the technique and at least 2 GPs (though primarily targeting the PMLGP. It is usual to obtain an acute reduction in the AH interval and increase of the Wenckebach's point. However, a short vagal stimulation usually shows a high-degree AV block, mainly during atrial pacing. In addition to electrophysiological parameters, the best endpoint for AV node denervation is to abolish AV block induced by left vagus nerve stimulation at the end of the procedure.

•Isolated AV block can be reproduced with controlled stimulation of the left vagus nerve and may be a useful tool during CNA in the treatment of functional AV block.

AF = atrial fibrillation; AV = atrioventricular; CNA = cardioneuroablation; GP = ganglionated plexus; PMLGP = posteromedial left ganglionated plexus.

^∗See Table 4 for more detailed information.