Long-Term Evaluation of the Vagal Denervation by Cardioneuroablation using Holter and Heart Rate Variability

ABSTRACT: Several disorders present reflex or persistent increase in vagal tone that may cause refractory symptoms even in a normal heart patient. Cardioneuroablation (CNA), the vagal denervation by RF ablation of the neuromyocardial interface, was developed to treat these conditions without pacemaker implantation. A theoretical limitation could be the reinnervation, that naturally grows in the first year, that could recover the vagal hyperactivity. This study aims to verify the vagal denervation degree in the chronic phase after CNA. Additionally, it intends to investigate the arrhythmias behavior after CNA. METHODS - prospective longitudinal study with intra-patient comparison of 83 very symptomatic cases without significant cardiopathy, submitted to CNA, 49(59%) male, 47.3±17 years-old, having vagal paroxysmal atrial fibrillation 58(70%) or neurocardiogenic syncope 25(30%), NYHA Class < II and absence of significant comorbidities. CNA was performed in both atria by interatrial septum puncture, with irrigated conventional catheter and electroanatomic reconstruction. Ablation targeted the neuromiocardial interface by fragmentation mapping (AFNests) using the Velocity Fractionation software, conventional recording and anatomical localization of the ganglionated plexi. There were compared the time and frequency domain of the heart rate variability (HRV) and arrhythmias in 24h Holter pre-, 1-year-post- and 2-year-postCNA. Clinical outpatient follow-up and serial Holter showed 80% asymptomatic cases at 40 months. RESULTS - Time and frequency domain HRV demonstrated significant decrease in all autonomic parameters, showing an important parasympathetic and sympathetic activity reduction at 2 yearspost-CNA (p0.05) suggesting that the reinnervation has halted. There was also an important reduction in all brady- and tachyarrhythmias pre- vs. post-CNA, (p<0.01). CONCLUSIONS ­ There is an important and significant vagal and sympathetic denervation after 2 years of CAN with a significant reduction in brady and tachyarrhythmia in the whole group. There were no complications.

Long-Term Evaluation of the Vagal Denervation by Cardioneuroablation Using Holter and Heart Rate Variability.

BACKGROUND: Several disorders present reflex or persistent increase in vagal tone that may cause refractory symptoms even in a normal heart patient. Cardioneuroablation, the vagal denervation by radiofrequency ablation of the neuromyocardial interface, was developed to treat these conditions without pacemaker implantation. A theoretical limitation could be the reinnervation, that naturally grows in the first year, that could recover the vagal hyperactivity. This study aims to verify the vagal denervation degree in the chronic phase after cardioneuroablation. Additionally, it intends to investigate the arrhythmias behavior after cardioneuroablation. METHODS: Prospective longitudinal study with intrapatient comparison of 83 very symptomatic cases without significant cardiopathy, submitted to cardioneuroablation, 49 (59%) male, 47.3±17 years old, having vagal paroxysmal atrial fibrillation 58 (70%) or neurocardiogenic syncope 25 (30%), New York Heart Association class0.05) suggesting that the reinnervation has halted. There was also an important reduction in all bradyarrhythmias and tachyarrhythmias pre-cardioneuroablation versus post-cardioneuroablation (P<0.01). CONCLUSIONS: There is an important and significant vagal and sympathetic denervation after 2 years of cardioneuroablation with a significant reduction in bradyarrhythmia and tachyarrhythmia in the whole group. There were no complications.

Ablation of "Background Tachycardia" in Long Standing Atrial Fibrillation: Improving the Outcomes by Unmasking a Residual Atrial Fibrillation Perpetuator.

BACKGROUND: Catheter ablation of long-standing persistent AF (LSAF) remains challenging. Since AF-Nest (AFN) description, we have observed that a stable, protected, fast source firing, namely "Background Tachycardia"(BT), could be hidden beneath the chaotic AF. Following pulmonary vein isolation (PVI)+AFN ablation one or more BT may arise or be induced in 30-40% of patients, which could be the culprit forAF maintenance and ablation recurrences. METHODS AND RESULTS: We studied 114 patients, from 322 sequential LSAF regular ablations, having spontaneous or induced residual BT after EGM-guided PVI+AFN ablation of LSAF; 55.6±11y/o, 97males (85.1%), EF=65.5±8%, LA=42.8±6.7mm. Macroreentrant tachycardias were excluded. Pre-ablationAF 12-leads ECG Digital processing(DP) and spectral analysis(SA) was performed searching for BT before AF ablation and its correlation with BT during ablation.After PVI, 38.1±9 AFN sites/patient and 135 sustained BTs (1-3, 1.2±0.5/patient) were ablated. BT cycle length(CL) was 246.3±37.3ms. In 79 patients presenting suitable DP for SA, the BT-CL was 241.6±34.3ms with intra procedure BT-CL correlation r=0.83/p<0.01. Following BT ablation, AF could not be induced. During FU of 13→60 months(22.8±12m), AF freedom for BT RF(+) vs. BT RF(-) groups were 77.9% vs. 56.4% (p=0.009), respectively. There was no significant complication. CONCLUSION: BT ablation following PVI and AFN ablation improved long-term outcomes ofLSAF ablation. BT is likely due to sustained microreentry, protected during AF by entry block. BT can be suspected by spectral analysis of the pre-ablation ECG and is likely one important AF perpetuator by causing electrical resonance of the AFN. This ablation strategy warrants randomized, multicenter investigation.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation--prospective study of 704 cases.

INTRODUCTION: Although 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. OBJECTIVE: This 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. METHODS: Seven 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. RESULTS: The 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. CONCLUSION: Mechanical 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.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation - prospective study of 704 cases / Método simplificado para proteção do esôfago durante a ablação por radiofrequência da fibrilação atrial - estudo prospectivo de 704 casos

Abstract Introduction: Although 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. Objective: This 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. Methods: Seven 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. Results: The 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. Conclusion: Mechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid ...

Resumo Introdução: Apesar de rara, a fístula átrio-esofágica é uma das complicações mais temidas na ablação por radiofrequência da fibrilação atrial pelo alto risco de mortalidade. Objetivo: Este é um estudo prospectivo controlado, realizado durante a ablação por radiofrequência da fibrilação atrial regular, para testar se o deslocamento do esôfago ao manipular o transdutor de ecocardiografia transesofágica poderia ser usado para a proteção de esôfago. Métodos: Setecentos e quatro pacientes (158 mulheres e 546 homens [22,4%/77,6%]; 52,8±14 [17-84] anos), com EF média igual a 0,66±0,8 e com fibrilação atrial refratária ao tratamento medicamentoso, foram submetidos à terapia híbrida com ablação por radiofrequência (isolamento convencional das veias pulmonares e ninhos de fibrilação atrial e ablação de taquicardia de background) com deslocamento do esôfago o mais longe possível do alvo da radiofrequência por manuseio do transdutor de ecocardiografia transesofágica. A temperatura luminal esofágica foi monitorada com e sem deslocamento em 25 pacientes. Resultados: O deslocamento esofágico significativo foi de 4 a 9,1 centímetros (5,9±0,8 cm). Em 680 dos 704 pacientes (96,6%), isso foi o suficiente para permitir a entrega completa e segura de radiofrequência (30W/40ºC/cateter irrigado ou 50W/60ºC/cateter de 8 milímetros) sem sobreposição do esôfago. As alterações médias de temperatura luminal esofágica com e sem deslocamento de esôfago foram de 0,11±0,13ºC versus 1,1±0,4ºC, respectivamente, P<0,01. A radiofrequência teve que ser interrompida em 68% dos pacientes sem deslocamento de esôfago devido ao aumento da temperatura luminal esofágica. Não houve nenhum caso, suspeito ou confirmado, de fístula átrio-esofágica. Foram observados apenas dois sangramentos superficiais causados por inserção do transdutor de ecocardiografia transesofágica. Conclusão: O deslocamento mecânico do esôfago pelo transdutor de ecocardiografia transesofágico durante ...