Selective right atrial cardioneuroablation in functional atrioventricular block

Cardioneuroablation: Catheter Vagal Denervation as a New Therapy for Cardioinhibitory Syncope

The vasovagal syncope is the most frequent cause of transient loss of consciousness, especially in young people without significant heart disease. The malignant cardioinhibitory form is caused by abrupt and intense vagal reflex with or without defined triggers. Refractory cases to preventive measures and pharmacological handling has been treated with definitive pacemaker implantation. Besides showing questionable results, pacemaker implantation is highly rejected by young patients. In the late 1990s, we proposed specific vagal denervation by catheter ablation and spectral mapping, for paroxysmal AF, functional bradyarrhythmias and severe cases of malignant cardioinhibitory syncope giving rise to cardioneuroablation. Recently, many authors worldwide have been reproducing the cardioneuroablation results where elimination or significant reduction of the vagal response were observed, which abolished symptoms in more than 75% of patients followed up to 14 years, without complications. Therefore, cardioneuroablation has shown to be a real therapeutic option in malignant syncope cardioinhibitory and in any exclusive vagal mediated bradyarrhythmia without the need for pacemaker implantation.

Cardioneuroablação: A Denervação Vagal por Cateter Como Nova Terapia para Síncope Cardioinibitória

A síncope vasovagal é a causa mais frequente de perda transitória de consciência, especialmente em jovens sem doença cardíaca significativa. A forma cardioinibitória maligna é causada por reflexo vagal abrupto e intenso com ou sem gatilhos definidos. Casos refratários a medidas preventivas e manuseio farmacológico foram tratados com implante definitivo de marcapasso. Além de apresentar resultados questionáveis, o implante de marcapasso é altamente rejeitado por pacientes jovens. No final dos anos 1990, propusemos uma denervação vagal específica por ablação do cateter e mapeamento espectral para FA paroxística, bradiarritmias funcionais e casos graves de síncope cardioinibitória maligna dando origem à cardioneuroablação. Recentemente, muitos autores em todo o mundo vêm reproduzindo os resultados da cardioneuroablação, onde se observou eliminação ou redução significativa da resposta vagal, o que aboliu sintomas em mais de 75% dos pacientes acompanhados por até 14 anos, sem complicações. Portanto a cardioneuroablação tem se mostrado uma verdadeira opção terapêutica na síncope cardioinibitória maligna e em qualquer bradiarritmia vagal exclusiva mediada sem a necessidade de implante de marcapasso.

Coincidental ganglionated plexus modification during radiofrequency pulmonary vein isolation and post-ablation arrhythmia recurrence

Aims

Vagal responses (VR) during left atrial ablation for atrial fibrillation (AF) treatment have been reported to be associated with less recurrences, presumably because they are a sign of ganglionated plexi modification. Our objective was to evaluate whether coincidentally elicited VR during left atrial ablation are associated with lower AF recurrence rates.

Methods and results

This is a post hoc analysis of a prospective study of 291 patients with paroxysmal AF undergoing radiofrequency pulmonary vein isolation (PVI). Vagal responses were defined as episodes of heart rate <40 bpm or asystole lasting >5 s elicited during energy application. Sixty-eight patients (23.4%) had a VR during ablation. In Kaplan-Meier analysis, mean recurrence-free survival was 449 days (95% confidence interval 411-488) in patients with VR when compared with 435 days (95% confidence interval 415-455) in those without (P = 0.310). The 12-month recurrence rate estimates were 25 and 27%, respectively. In an unadjusted Cox model, VR was associated with an odds ratio for recurrence of 0.77 (95% confidence interval 0.46-1.28).

Conclusion

Coincidentally elicited VR during radiofrequency PVI in patients with paroxysmal AF do not appear to be related to lower risk of arrhythmia recurrence. This may mean that, even if a VR is truly a sign of coincidental ablation of a ganglionated plexus, this does not necessarily mean that a therapeutic modification has been effected, at least to a degree associated with clinical benefit.