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Background: Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra‐cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA. Objective: This study aimed to compare the long‐term follow‐up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS. Method: A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1 ± 2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing. Results: Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow‐up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9 ± 20 months for the NoECVS group (p =.24). Notably, syncope recurrence was significantly lower in the ECVS group (two cases vs. four cases, Log Rank p =.04). Moreover, the Hazard ratio revealed a fivefold higher risk of syncope recurrence in the NoECVS group. Conclusion: This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation. [ABSTRACT FROM AUTHOR]

Background: Despite good results, atrial fibrillation (AF) ablation shows a relatively high recurrence rate. Therefore, we sought to verify whether endocardial denervation by cardioneuroablation (CNA) can change the AF recurrence post-pulmonary vein isolation (PVI). Objective: To compare the long-term AF recurrence post-PVI versus PVI, plus vagal denervation (PVI+CNA) by CNA with vagal denervation confirmation by extracardiac vagal stimulation (ECVS). Methods: Case-control study of 127 patients, 104 (81.9%) males, 53.7 ± 12 years-old, with paroxysmal 71 (55.9%) or persistent 56 (44.1%) symptomatic AF, refractory to medications without cardiopathy, LA = 39.8 ± 6.8, EF = 0.66 ± 0.55. Two equivalent groups were established: PVI alone (55 cases) and PVI+CNA (72 cases). The ECVS was performed by intravenous catheter, near the jugular foramen with 50Hz/50microsec/1V/Kg/up to 70V. Endocardial CNA was biatrial over the four main ganglionated plexus and in the AF-Nests regions tagged by fractionation software. The endpoint of CNA was the elimination of the vagal effect induced by ECVS. Results: PVI was achieved in all cases. ECVS effectively induced a vagal reaction in all PVI+CNA patients, and it was possible to eliminate the vagal effect in 88.9% of cases. In 11.1% of cases, there was a slight residual vagal response. Patients were followed up to 45 months (mean FU = 21.4 ± 14.2 and 20.4 ± 14.3 months). Recurrences were 17 in the PVI group, and four in the PVI+CNA group: Log-Rank p < 0.00, HR: 5.38 (1.78-16.29, p = 0.003). No major complications occurred. Conclusion: Addition of vagal denervation to PVI, with validation of the vagal denervation by ECVS, significantly increased the success rate of the PVI with a marked reduction in AF relapses without increasing complications. [ABSTRACT FROM AUTHOR]

Background By studying the spectrum of atrial potentials by fast Fourier transform (FFT) we have found two types of atrial muscle: the compact (CM) and the fibrillar (FM) myocardium. The former presents normal in-phase conduction inferring a great number of cellular connections, long-lasting refractoriness and leftward FFT-shift. The latter shows anisotropic out-of-phase conduction, fewer cellular connections, short refractoriness and a segmented right-FFT-shift. The compact is the normal predominant muscle and the fibrillar is different and may be neural input, vein insertion, interatrial (1A) septum, left atrial (LA) roof, etc. or pathological tissue, being so by loss of cellular connections this is a possible mechanism for conversion of compact into fibrillar-like myocardium. During atrial fibrillation (AF), clusters of FM (AF nests) present higher frequencies than any surrounding tissue. Purpose The purpose was to describe a new method for paroxysmal AF RF-ablation targeting AF nests. Method Forty patients, six control and 34 having idiopathic drug-refractory paroxysmal or persistent AF were studied and treated. Two catheters were placed in the LA by transseptal approach. RF (30–40 J/60–70 °C) was applied to all sites outside the pulmonary veins (PV) presenting right-FFT-shift (AF nests). Results Numerous AF nests were found in 34/34 AF patients and only in 1/6 controls (only in this case it was possible to induce AF despite an absence of AF history). The main FM sites were: LA roof, LA septum, close to the insertion of the superior PV, near the insertion of the inferior PV, LA posterior wall, RA near the superior vena cava insertion, RA lateral and anterior wall and the right IA septum. Ablation of all AF nests near PV insertions resulted in 35 PV isolations. After 9.9 ± 5 months only two AF patients presented relapse of a different AF form (coarse AF) which was very well controlled with medication previously ineffective. The AF was more frequent as the ratio FM/CM increased. Conclusions The RF-ablation of AF nests decreasing the fibrillar/compact myocardium ratio eliminated 94% of the paroxysmal AF in patients in the FU of 9.9 ± 5 months. The AF nests may be easily identified by spectral analysis and seem to be the real AF substrate. Paroxysmal AF may be cured or controlled by applying RF in several places outside the PV and, thereby, avoiding PV stenosis. [ABSTRACT FROM PUBLISHER]

Background: By studying the spectrum of atrial potentials by fast Fourier transform (FFT) we have found two types of atrial muscle: the compact (CM) and the fibrillar (FM) myocardium. The former presents normal in-phase conduction inferring a great number of cellular connections, long-lasting refractoriness and leftward FFT-shift. The latter shows anisotropic out-of-phase conduction, fewer cellular connections, short refractoriness and a segmented right-FFT-shift. The compact is the normal predominant muscle and the fibrillar is different and may be neural input, vein insertion, interatrial (1A) septum, left atrial (LA) roof, etc. or pathological tissue, being so by loss of cellular connections this is a possible mechanism for conversion of compact into fibrillar-like myocardium. During atrial fibrillation (AF), clusters of FM (AF nests) present higher frequencies than any surrounding tissue., Purpose: The purpose was to describe a new method for paroxysmal AF RF-ablation targeting AF nests., Method: Forty patients, six control and 34 having idiopathic drug-refractory paroxysmal or persistent AF were studied and treated. Two catheters were placed in the LA by transseptal approach. RF (30-40 J/60-70 degrees C) was applied to all sites outside the pulmonary veins (PV) presenting right-FFT-shift (AF nests)., Results: Numerous AF nests were found in 34/34 AF patients and only in 1/6 controls (only in this case it was possible to induce AF despite an absence of AF history). The main FM sites were: LA roof, LA septum, close to the insertion of the superior PV, near the insertion of the inferior PV, LA posterior wall, RA near the superior vena cava insertion, RA lateral and anterior wall and the right IA septum. Ablation of all AF nests near PV insertions resulted in 35 PV isolations. After 9.9 +/- 5 months only two AF patients presented relapse of a different AF form (coarse AF) which was very well controlled with medication previously ineffective. The AF was more frequent as the ratio FM/CM increased., Conclusions: The RF-ablation of AF nests decreasing the fibrillar/compact myocardium ratio eliminated 94% of the paroxysmal AF in patients in the FU of 9.9 +/- 5 months. The AF nests may be easily identified by spectral analysis and seem to be the real AF substrate. Paroxysmal AF may be cured or controlled by applying RF in several places outside the PV and, thereby, avoiding PV stenosis.