Long-term outcomes of cardioneuroablation with and without extra-cardiac vagal stimulation confirmation in severe cardioinhibitory neurocardiogenic syncope.

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.

Targets and End Points in Cardiac Autonomic Denervation Procedures.

BACKGROUND: Autonomic denervation is an alternative approach for patients with symptomatic bradycardia. No consensus exists on the critical targets and end points of the procedure. The aim of this study was to identify immediate end points and critical atrial regions responsible for vagal denervation. METHODS AND RESULTS: We enrolled 14 patients (50% men; age: 34.0±13.8 years) with cardioinhibitory syncope, advanced atrioventricular block or sinus arrest, and no structural heart disease. Anatomic mapping of ganglionated plexuses was performed, followed by radiofrequency ablation. Heart rate, sinus node recovery time, Wenckebach cycle length, and atrial-His (AH) interval were measured before and after every radiofrequency pulse. Wilcoxon signed-rank test was used for comparison. Significant shortening of the R-R interval (P=0.0009), Wenckebach cycle length (P=0.0009), and AH intervals (P=0.0014) was observed after ablation. The heart rate elevation was 23.8±12.5%, and the Wenckebach cycle length and AH interval shortening was 18.1±11% and 24.6±19%, respectively. Atropine bolus injection (0.04 mg/kg) did not increase heart rate further. Targeting a single spot of the left side (64% of the patients) or right side (36%) of the interatrial septum was observed to be responsible for ≥80% of the final R-R and AH interval shortening during ablation. CONCLUSIONS: Targeting specific sites of the interatrial septum is followed by an increase in heart rate and atrioventricular nodal conduction properties and might be critical for vagal attenuation. The R-R interval, Wenckebach cycle length, and AH interval shortening, associated with a negative response to atropine, could be considered immediate end points of the procedure.

Catheter ablation of severe neurally meditated reflex (neurocardiogenic or vasovagal) syncope: cardioneuroablation long-term results.

AIMS: Neurally meditated reflex or neurocardiogenic or vasovagal syncope (NMS) is usually mediated by a massive vagal reflex. This study reports the long-term outcome of NMS therapy based on endocardial radiofrequency (RF) catheter ablation of the cardiac vagal nervous system aiming permanent attenuation or elimination of the cardioinhibitory reflex (cardioneuroablation). METHODS AND RESULTS: A total of 43 patients (18F/25M, 32.9 ± 15 years) without apparent cardiopathy (left ventricular ejection fraction=68.6 ± 5%) were included. All had recurrent NMS (4.7 ± 2 syncope/patient) with important cardioinhibition (pauses=13.5 ± 13 s) at head-up tilt test (HUT), normal electrocardiogram (ECG), and normal atropine test (AT). The patients underwent atrial endocardial RF ablation using spectral mapping to track the neurocardiac interface (AF Nest Mapping). The follow-up (FU) consisted of clinical evaluation, ECG (1 month/every 6 months/or symptoms), Holter (every 6 months/or symptoms), HUT (≥ 4 months/or symptoms), and AT (end of ablation and ≥ 6 months). A total of 44 ablations (48 ± 9 points/patient) were performed. Merely three cases of spontaneous syncope occurred in 45.1 ± 22 months (two vasodepressor, one undefined). Only four partial cardioinhibitory responses occurred in post-ablation HUT without pauses or asystole (sinus bradycardia). Long-term AT (21.7 ± 11 months post) was negative in 33 (76.7%, P < 0.01), partially positive in 7(16.3%), and normal in three patients only (6.9%) reflecting long-term vagal denervation (AT-Δ%HR pre 79.4% × 23.2% post). The post-ablation stress test and Holter showed no abnormalities. No major complications occurred. CONCLUSION: Endocardial RF catheter ablation of severe neurally meditated reflex syncope prevented pacemaker implantation and showed excellent long-term results in well selected patients. Despite no action in vasodepression it seems to cause enough long-term vagal reflex attenuation, eliminating the cardioinhibition, and keeping most patients asymptomatic. Indication was based on clinical symptoms, reproduction of severe cardioinhibitory syncope, and normal atropine response.

"Cardioneuroablation"--new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation.

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.

Marcapasso com função "rate-drop response" no tratamento da síndrome de hipersensibilidade do seio carotídeo associada à disfunção sinusal, síncope vasovagal e hipotensão ortostática / \"Rate-drop response\" cardiac pacing for carotid sinus syndrome associated with sinus node disfunction vasovagal syncope and orthostatic hypotension

A associação entre síndrome de hipersensibilidade do seio carotídeo (SHSC) e bradicardia ou disfunção sinusal e síncope vasovagal ou hipotensão ortostática pode ocorrer em pacientes idosos, tornando-se um complicador no manejo terapêutico dessa entidade. O marcapasso artificial definitivo (MP) tem se constituído no tratamento de escolha de pacientes com SHSC e síncope recorrente. O objetivo deste estudo prospectivo é avaliar a performance do MP com programação denominada "rate drop response" (RDR) em um subgrupo de pacientes portadores de SHSC associada à bradicardia ou disfunção do nó sinusal, a sintomas de hipotensão ortostática freqüentes e à síncope vasovagal clássica. Cinco pacientes, sendo quatro do sexo masculino, com média de idade de 71 anos (62 a 78 anos), média de 7 eventos sincopais (4 a 12 síncopes) e com duração dos sintomas variando de 3 meses a 20 anos, tiveram diagnóstico de SHSC confirmado por meio de massagem do seio carotídeo (MSC) em posição supina e/ou durante teste de inclinação. O tratamento inicial pela associação de drogas mostrou-se ineficaz. Foram submetidos, então, a implante de MP THERA DR (2 pcts) e KAPPA DR (3 pcts) com função RDR. Após programação individualizada da função RDR, ocorreu negativação da resposta à MSC e ao teste de inclinação. Foi necessária a manutenção da terapêutica farmacológica em todos os casos para controle do componente vasodepressor da SHSC, síncope vasovagal e dos sintomas de hipotensão ortostática. Em um seguimento médio de 18 meses (variando de 7 a 31 meses), um paciente apresentou recorrência de síncope e outro faleceu de infarto agudo do miocárdio. Concluímos que a utilização do MP bicameral com possibilidade de programação da função RDR, aliada à terapêutica farmacológica otimizada, mostrou-se uma abordagem terapêutica eficaz nesse subgrupo de pacientes

O uso do marcapasso cardíaco e da fludocortisona no tratamento da síncope neurocardiogênica maligna / Pacemaker and fludocortisone as treatment of malignant neurocardiogenic syncope

A síncope neurocardiogênica é uma anormalidade comum e com prognóstico geralmente benigno. Entretanto, um subgrupo de pacientes com esta anormalidade pode apresentar episódios de bradicardia ou assistolia acentuada, sendo considerados portadores da síncope neurocardiogênica maligna. O marcapasso de dupla-câmara, como terapêutica isolada, pode não ser suficiente para eliminar tais episódios, especialmente na presença de um componente vasodepressor importante. Descreve-se o caso clínico de um paciente que foi tratado com sucesso com a combinação do marcapasso dupla-câmara e da fludocortisona