Cardiac neuroablation is a new technique for management of patients with dominantly adverse parasympathetic autonomic influence. The technique is based on radiofrequency (RF) ablation of autonomic connections in the three main ganglia around the heart. Their connections are identified by Fast-Fourier Transforms (FFTs) of endocardial signals: sites of autonomic nervous connections show fractionated signals with FFTs shifted to the right. In contrast, normal myocardium without these connections does not show these features. RF-ablation is thought to inflict permanent damage on the parasympathetic autonomic influence because its cells are adjacent to the heart whereas sympathetic cells are remote. Twenty-one patients with a mean age of 48 years, neurally mediated reflex syncope in six, functional high grade atrioventricular block in seven and sinus node dysfunction in 13 (there is overlap between the second and third groups) were treated. Follow-up for a mean of 9.2 months demonstrated success in all cases with relief of symptoms. No complications occurred.

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.

A 23-year-old-female patient had undergone a very successful gastric banding surgery to treat obesity. Six months later she began to present recurrent syncope due to very frequent, intermittent high-degree AV block referred to as pacemaker implantation. The electrophysiological study showed impaired AV nodal conduction but the His-Purkinje conduction was preserved. Partial catheter radiofrequency ablation of the cardiac autonomic nervous system guided by spectral endocardial mapping (cardioneuroablation) was performed. The electrophysiological parameters were normalized. Holter recordings were normal and the patient was asymptomatic with normal life without pacemaker implantation in a follow-up 21 months later.

IntroductionAlthough rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality.ObjectiveThis is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection.MethodsSeven hundred and four patients (158 F/546M [22.4%/77.6%]; 52.8±14 [17-84] years old), with mean EF of 0.66±0.8 and drug-refractory atrial fibrillation were submitted to hybrid radiofrequency catheter ablation (conventional pulmonary vein isolation plus AF-Nests and background tachycardia ablation) with displacement of the esophagus as far as possible from the radiofrequency target by transesophageal echocardiography transducer handling. The esophageal luminal temperature was monitored without and with displacement in 25 patients.ResultsThe mean esophageal displacement was 4 to 9.1cm (5.9±0.8 cm). In 680 of the 704 patients (96.6%), it was enough to allow complete and safe radiofrequency delivery (30W/40ºC/irrigated catheter or 50W/60ºC/8 mm catheter) without esophagus overlapping. The mean esophageal luminal temperature changes with versus without esophageal displacement were 0.11±0.13ºC versus 1.1±0.4ºC respectively, P<0.01. The radiofrequency had to be halted in 68% of the patients without esophageal displacement because of esophageal luminal temperature increase. There was no incidence of atrioesophageal fistula suspected or confirmed. Only two superficial bleeding caused by transesophageal echocardiography transducer insertion were observed.ConclusionMechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid esophageal thermal lesion. In most cases, the esophageal displacement was sufficient to allow safe radiofrequency application without esophagus overlapping, being a convenient alternative in reducing the risk of atrioesophageal fistula.

The SM in sinus rhythm can be used in the ablation of AF nests. During the AF, the AF nests present a reactive-resonant pattern and the compact myocardium is passive, stimulated by the high frequency of the BT. After the ablation of the AF nests and the BT, it was not possible to reinduce the sustained AF. The Ablation of AF nests outside the pulmonary veins showed to be safe and highly effective in the cure and/or clinical control of the AF.