Cardioneuroablation: Where are we at?

Since its original description in 2005, catheter ablation techniques, commonly called cardioneuroablation, have emerged as a potential strategy for modulating autonomic function. Multiple investigators have provided observational data on the potential benefits of this technique in a variety of conditions associated with or exacerbated by increased vagal tone such as vasovagal syncope, functional atrioventricular block, and sinus node dysfunction. Patient selection, current techniques including the various mapping strategies, clinical experience, and limitations of cardioablation are reviewed. Finally, while cardioneuroablation has potential to be a treatment option for selected patients with symptoms mediated by hypervagotonia, the document outlines the important knowledge gaps that currently exist and the necessary next steps required before this technique can be widely implemented into clinical practice.

Cardioneuroablation: where are we at?

Since its original description in 2005, catheter ablation techniques, commonly called cardioneuroablation, have emerged as a potential strategy for modulating autonomic function. Multiple investigators have provided observational data on the potential benefits of this technique in a variety of conditions associated with or exacerbated by increased vagal tone such as vasovagal syncope, functional atrioventricular block, and sinus node dysfunction. Patient selection, current techniques including the various mapping strategies, clinical experience, and limitations of cardioablation are reviewed. Finally, while cardioneuroablation has potential to be a treatment option for selected patients with symptoms mediated by hypervagotonia, the document outlines the important knowledge gaps that currently exist and the necessary next steps required before this technique can be widely implemented into clinical practice.

Atrial Fibrillation Ablation in Systolic Dysfunction: Clinical and Echocardiographic Outcomes / Ablação da Fibrilação Atrial na Disfunção Sistólica: Evolução Clínica e Ecocardiográfica

Background: Heart failure and atrial fibrillation (AF) often coexist in a deleterious cycle. Objective: To evaluate the clinical and echocardiographic outcomes of patients with ventricular systolic dysfunction and AF treated with radiofrequency (RF) ablation. Methods: Patients with ventricular systolic dysfunction [ejection fraction (EF) <50%] and AF refractory to drug therapy underwent stepwise RF ablation in the same session with pulmonary vein isolation, ablation of AF nests and of residual atrial tachycardia, named "background tachycardia". Clinical (NYHA functional class) and echocardiographic (EF, left atrial diameter) data were compared (McNemar test and t test) before and after ablation. Results: 31 patients (6 women, 25 men), aged 37 to 77 years (mean, 59.8±10.6), underwent RF ablation. The etiology was mainly idiopathic (19 p, 61%). During a mean follow-up of 20.3±17 months, 24 patients (77%) were in sinus rhythm, 11 (35%) being on amiodarone. Eight patients (26%) underwent more than one procedure (6 underwent 2 procedures, and 2 underwent 3 procedures). Significant NYHA functional class improvement was observed (pre-ablation: 2.23±0.56; postablation: 1.13±0.35; p<0.0001). The echocardiographic outcome also showed significant ventricular function improvement (EF pre: 44.68%±6.02%, post: 59%±13.2%, p=0.0005) and a significant left atrial diameter reduction (pre: 46.61±7.3 mm; post: 43.59±6.6 mm; p=0.026). No major complications occurred. Conclusion: Our findings suggest that AF ablation in patients with ventricular systolic dysfunction is a safe and highly effective procedure. Arrhythmia control has a great impact on ventricular function recovery and functional class improvement. .

Fundamento: Insuficiência cardíaca e fibrilação atrial (FA) frequentemente coexistem em um ciclo deletério. Objetivo: Avaliar a evolução clínica e ecocardiográfica de portadores de disfunção ventricular e FA tratados com ablação por radiofrequência (RF). Métodos: Portadores de disfunção sistólica [fração de ejeção (FE) < 50%] e FA rebelde a tratamento clínico foram submetidos à ablação por RF escalonada em três etapas na mesma sessão com isolamento das veias pulmonares, ablação dos ninhos de FA, pesquisa e ablação de taquicardias atriais e "taquicardia de background". Os dados clínicos (classe funcional da NYHA) e ecocardiográficos (FE; diâmetro do átrio esquerdo) pré- e pós-procedimento foram comparados (teste de McNemar e teste t, respectivamente). Resultados: 31 pacientes (6 mulheres, 25 homens) de 37 a 77 anos (média, 59,8 ± 11 anos) foram submetidos à ablação por RF. A cardiopatia foi predominantemente idiopática (19 p; 61%). Na evolução média de 20,3 ± 17 meses, 24 pacientes (77%) estavam em ritmo sinusal, sendo 11 (35%) com amiodarona. Oito pacientes (26%) foram submetidos a mais de um procedimento (6 submetidos a 2 procedimentos e 2 a 3 procedimentos). Observou-se melhora expressiva da classe funcional da NYHA (pré-ablação: 2,23 ± 0,56; pós: 1,13 ± 0,35; p < 0,0001). A avaliação ecocardiográfica evolutiva também mostrou melhora significativa da função ventricular (FE pré: 44,68% ± 6,02%; pós: 59% ± 13,2%; p = 0,0005) e redução significativa no diâmetro do átrio esquerdo (pré: 46,61 ± 7,3 mm; pós: 43,59 ± 6,6 mm; p = 0,026). Não ocorreram complicações maiores. Conclusão: Os resultados deste estudo sugerem que ablação de FA em portadores de disfunção ventricular seja um procedimento seguro e com eficácia elevada a médio prazo. O controle da arritmia tem grande impacto na recuperação da função ventricular e na melhora clínica avaliada pela classe funcional. .

Atrial fibrillation ablation in systolic dysfunction: clinical and echocardiographic outcomes.

BACKGROUND: Heart failure and atrial fibrillation (AF) often coexist in a deleterious cycle. OBJECTIVE: To evaluate the clinical and echocardiographic outcomes of patients with ventricular systolic dysfunction and AF treated with radiofrequency (RF) ablation. METHODS: Patients with ventricular systolic dysfunction [ejection fraction (EF) <50%] and AF refractory to drug therapy underwent stepwise RF ablation in the same session with pulmonary vein isolation, ablation of AF nests and of residual atrial tachycardia, named "background tachycardia". Clinical (NYHA functional class) and echocardiographic (EF, left atrial diameter) data were compared (McNemar test and t test) before and after ablation. RESULTS: 31 patients (6 women, 25 men), aged 37 to 77 years (mean, 59.8 ± 10.6), underwent RF ablation. The etiology was mainly idiopathic (19 p, 61%). During a mean follow-up of 20.3 ± 17 months, 24 patients (77%) were in sinus rhythm, 11 (35%) being on amiodarone. Eight patients (26%) underwent more than one procedure (6 underwent 2 procedures, and 2 underwent 3 procedures). Significant NYHA functional class improvement was observed (pre-ablation: 2.23 ± 0.56; postablation: 1.13 ± 0.35; p < 0.0001). The echocardiographic outcome also showed significant ventricular function improvement (EF pre: 44.68% ± 6.02%, post: 59% ± 13.2%, p = 0.0005) and a significant left atrial diameter reduction (pre: 46.61 ± 7.3 mm; post: 43.59 ± 6.6 mm; p = 0.026). No major complications occurred. CONCLUSION: Our findings suggest that AF ablation in patients with ventricular systolic dysfunction is a safe and highly effective procedure. Arrhythmia control has a great impact on ventricular function recovery and functional class improvement.

Teste ergométrico em portadores de dispositivos cardíacos eletrônicos implantáveis / Exercise testing in patients with cardiac implantable electronic devices

O número de pacientes com dispositivos eletrônicos vem crescendo substancialmente nos últimos anos. Marca-passos com inúmeras programações e desfibriladores com ou sem ressincronizadores, cada vez mais comuns, apresentam-se com traçados eletrocardiográficos confundidores. Assim, é necessária a compreensão de princípios básicos e técnicos pelos clínicos, além da integração entre estes e os eletrofisiologistas. O conhecimento de tais princípios básicos é fundamental na condução desses pacientes, de modo que o ergometrista deve estar ciente do tipo de dispositivo, programação, frequência mínima e máxima de comando, presença de desfibrilador, bem como suas frequências de terapias e desfibrilação. Assim, promover-se-á maior segurança durante provas funcionais (teste ergométrico e ergoespirométrico) e programas de treinamento físico. Este artigo de revisão tem por objetivo descrever diversos pontos de interesse na realização do teste ergométrico em portadores de dispositivos eletrônicos.

The number of patients fitted with cardiac implantable electronic devices has grown substantially over the past few years. Pacemakers with countless programming options and defibrillators with or without resynchronization devices are increasingly more common, with confusing electrocardiographic findings. Consequently, general practitioners must understand their basic principles and techniques, in addition to developing stronger links with electrophysiologists. Knowledge of these basic principles is crucial for managing these patients, meaning that people administering ergometric testing must be aware of the type of device and its programming, minimum and maximum command frequency and defibrillator, as well as its treatment and defibrillation frequencies. This will ensure greater safety during ergometric and ergospyrometric exercise testing and exercise programs. This paper describes several points of interest in ergometric testing for patients fitted with cardiac implantable electronic devices.

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.

Ablación de la fibrilación auricular por catéter con radiofrecuencia guiada por mapeo espectral de los Nidos de FA en ritmo sinusal / Atrial fibrillation catheter RF-ablation guide

Usando el mapeo espectral endocárdio en ritmo sinusal nosotros podemos definir dos tipos de miocardio auricular: el fibrilar con espectro segmentado hacia la derecha - llamado Nido-FA (NFA) - y el compacto con espectro no segmentado hacia la izquierda. Al inducir FA nosotros hemos observado constantemente activación muy desorganizada sobre los Nidos-FA [tejido resonante reactivo] mientras el compacto mantiene una activación bien regular [ tejido pasivo]. Ambos son activados por una taquicardia protegida de alta frecuencia "Taquicardia de Background" (TB). Describir el tratamiento de la FA a través de la ablación - RF de los Nidos-FA y la TB. 92 p (76 H, 52,4 ± 11 a) con FA refractaria muy frecuente, 56 paroxístina, 25 persistente, 11 permanente sin cardiopatía significativa (AI 41, 9 ± 5mm). 1- Ablación- RF con catéter de los NFA [4/8 mm-60°/30-40J/30s] guiado por mapeo espectral en ritmo sinusal fuera de las venas pulmonares (VP); 2- Estimulación auricular (300 ppm); 3- Adicional ablación de los NFA cuando era inducida FA; 4- Ablación de TB focal o Flutter cuando eran inducidos; 4 - Seguimiento Clínico SC (EKG/Holter). Una media de 50 ± 18 nidos-FA / p fueron tratados. Después de SC 0 11,3 ± 8 meses 81p (88%) no tenía FA (28,3 % previamente utilizaban drogas AA no eficaces). Después de ablación los NFA: fue imposible reinducir FA en 61p (71 %); en 31p (29%) solo FA no sostenida (< 10s) fue inducida; TB fue inducida y tratada en 24p (26%). Dos derrames pericárdicos ocurrieron (tratada en 24p (26%). Dos derrames pericárdicos ocurrieron (tratada en 24p (26%). Dos derrames pericárdicos ocurrieron (tratados 1 clínicamente y 1 quirúrgicamente) descrito utilizando una específica y no más usada vaina. El mapeo espectral de los Nidos - FA fue fácil de hallar y ablacionar; Durante la FA los Nidos _ FA juegan un papel resonante reactivo mientras el compacto juega un papel pasivo, uno o ambos son activados por la TB de elevada frecuencia; Después de la ablación de los...

Using endocardial spectral mapping in sinus rhythm we found two kinds of atrial myocardium: fibrillar with a rightward - segmented spectrum - named AF - Nest (AFN) - and compact with a leftward non - segmented spectrum. Inducing AF we have consistently observed very highly disorganized activation only in the AF - Nest [reactive resonant tissue] while the compact myocardium maintains well - organized, predominantly regular activation [passive tissue]. Both are activated by a high frequency protected tachycardia "Background Tachycardia" (BT). To describe treatment of AF by AF - Nests and BT catheter RF - ablation. 92 (76 males, 52.4 ± 11 y) with very frequent refractory AF, paroxysmal in 56, persistent in 25, and permanent in 11 without any significant cardiopathy (LA 41. 9 ± 5mm). 1 - AFN Catheter RF ablation [4/8mm - 60°/30-40J/30s] guided by spectral mapping in sinus rhythm outside the pulmonary veins (PV); 2 - Atrial stimulation (300ppm); 3 - AFN additional ablation if AF induced; 4 - BT focal or flutter ablation if induced; 4 - Clinical FU (EKG/Holter). A mean of 50 ± 18 AF nests/person were treated. After 11. 3 ± 8 months of follow up, 81 (88%) patients had no AF (28. 3 % previously on no effective AA drugs). After AFN ablations, it Was not possible to reinduce AF in 61 (71%) cases. In 31 patients (29 %) only non - sustained AF (< 10s) was induced; BT was induced and treated in 24 patientns (26%). Two pericardial effusions occurred (1 clinically and 1 surgically treated) related to an isolated cause and the other to a sheath no longer in use. Using spectral mapping, AF - Nests were easily found and ablated. During AF - Nests play a reactive resonant role while the compact myocardium plays a passive one, both activated by the high frequency BT. After AF - nest and BT ablations it was not possible to reinduce sustained AF; AF - nest and BT ablation around the PV is safe, feasible and very efficient for the cure or control of AF.

"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.