Figure Legends
Figure 1 - Extracardiac Vagal Stimulation Methodology: A: The ECVS is
performed without direct contact with the vagus nerve through a specific
Vagal Stimulator or a Neuro-Stimulator using pulses with an amplitude of
1V/Kg of body weight up to a maximum of 70V with 50microseconds and
frequency of 50Hz; B: Schematic of the catheter inside the right or left
internal jugular vein; C: Diagram of the anatomy of a section of the
cervical region showing the close proximity of the vagus nerve and the
internal jugular vein; D: anteroposterior radiological view of the
position of the vagal stimulation catheter. The best stimulation site is
usually from the lower limit of the orbit to the root of the wisdom
tooth.
Figure 2 - ECVS Methodology. In the ECVS Group, the ECVS was used for
gradual control of CNA and for the endpoint. A: before CNA, a sinus
arrest is observed under ECVS. It is the usual response to ECVS in
normal people due to sinus node suppression; B: When ECVS is performed
with atrial pacing 10 to 20 ppm above the previous sinus rate before
CNA, high-grade AV block is usually observed due to AV node suppression;
C:ECVS applied after the CNA, obtaining a total absence of a vagal
effect. There is no more sinus arrest, sinus pause, bradycardia or AV
block. This was the expected endpoint in this group of patients.
Figure 3 - A: Schematic of endocardial sites usually ablated during CNA.
As the GPs are not visible, the sites of interest are assumed to be
anatomically close and numbered from 1 to 4. In addition to the GP
regions, the most important area for the CNA is the P Point located on
the left side of the interatrial septum. In cases of more difficult
denervation, additional areas are ablated such as the roof of the
coronary sinus, the region of the Marshall’s vein, superior vena cava,
anterolateral wall of the right atrium, the Waterston groove and any
other area indicated by the fractionation mapping; B: Schematic of the
sites of the four main ganglionated plexuses. Site 1: between superior
vena cava and aorta; Site 2: antrum of the right pulmonary veins; Site
3: Confluence of the coronary sinus ostium and the inferior vena cava;
Site 4: Insertion of the left pulmonary veins.
Figure 4 - A: Kaplan-Meier survival curves showing the free probability
of syncope in the ECVS group (CNA controlled with ECVS) and in the
NoECVS group (CNA without ECVS); B: Hazard cumulative risk curves for
the possibility of recurrence comparing the CNA controlled with ECVS
group with the CNA group without ECVS control.
Figure 5 - Fractionation software. In the normal heart, vagal
innervation can be indirectly identified through AF-Nests by spectral
mapping. Based on this method, we developed the Fractionation software
that allows the identification of AF-Nests in the electroanatomical
model without the need for spectral analysis. Additionally, innervation
can be approached by approximation by using the assumed position of the
GPs. However, in many cases, due to anatomical variations, the
fractionation map is necessary to complement the anatomical method and
obtain complete denervation.