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.

Associação de Cardiopathia fantastica e Dermatitis artefacta em paciente submetido a implante de marcapasso / Combination of Cardiopathia fantastica and Dermatitis artefacta in patients undergoing permanent pacemaker implantation

Cardiopathia fantastica é o termo utilizado para a variante cardíaca da síndrome de Munchausen, condição na qual o paciente busca atendimento médico repetidamente por doenças factícias. Relatamos um caso de síncope induzida por administração inadequada de fármacos cronotrópicos negativos, que resultou em implante de marcapasso definitivo, seguido de reações cutâneas sobre a loja do marcapasso. O acompanhamento da paciente mostrou que as alterações cutâneas eram lesões factícias (Dermatitis artefacta). Apresentamos também uma breve revisão sobre as reações alérgicas a dispositivos cardíacos eletrônicos implantáveis, abrangendo sua fisiopatologia e alternativas terapêuticas disponíveis.

Cardiopathia fantastica is the cardiac variant of Munchausen syndrome, a condition where patients repeatedly seek medical consultation for factitious diseases. We report a case of syncope induced by an inadequate administration of negative chronotropic drugs, which resulted in permanent pacemaker implantation, followed by the appearance of cutaneous reactions over the pacemaker pocket. This patient´s follow-up showed that the cutaneous disease consisted of factitious lesions (Dermatitis artefacta). We also present a brief review on allergic reactions to cardiac implantable electronic devices, including its pathophysiology and available therapeutic strategies.

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.

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.

Bradiarritmias / Bradiarrhythimy

Considera-se bradiarritmia uma frequência cardíaca menor que 60 bpm.Evidentemente esse conceito é relativo à situação metabólica e à idade do paciente, mesmo porque uma frequência cardíaca de 50 bpms ou menos é normal durante o sono ou em pacientes idosos, assim como uma frequência de 70bpm constitui bradicardia em recém-nascidos ou em pacientes com febre. Isso demonstra que o diagnóstico de bradiarritmia depende do quadro clínico do paciente.

Conceitos básicos na estimulação cardíaca / Cardiacal estimulation basic concepts

A estimulação cardíaca é possível com relativa facilidade graças à natureza sincicial do miocárdio, que funciona como uma única célula. Um estímulo aplicado em qualquer parte do miocárdio propaga-se imediatamente , por condução muscular para todas as células, sem necessidade de inervação ou de mediadores químicos, devido à existência, entre as células mocárdicas, dos discos intercalares, que são verdadeiras sinapses elétricas altamente eficazes.