Electroanatomic-mapping-guided cardioneuroablation versus combined approach for vasovagal syncope: a cross-sectional observational study

Ablation of myocardial autonomic ganglion plexus in the treatment of bradyarrhythmia A one-arm interventional study

OBJECTIVES

To study the complications and effectiveness of the treatment of chronic arrhythmias with cardiac Ganglion Plexus (GP) ablation, and to explore the value of the treatment of chronic arrhythmias with GP ablation.

METHODS

This study was a one-arm interventional study of patients from the first hospital of Xinjiang Medical University and the People's Hospital of Xuancheng City admitted (09/2018-08/2021) because of bradyarrhythmia. The left atrium was modeled using the Carto3 mapping system. The ablation endpoint was the absence of a vagal response under anatomically localized and high-frequency stimulation guidance. Postoperative routine follow-up was conducted. Holter data at 3-, 6-, and 12-months were recorded.

RESULTS

Fifty patients (25 male, mean age 33.16 ± 7.89 years) were induced vagal response by either LSGP, LIGP, RAGP, or RIGP. The heart rate was stable at 76 bpm, SNRT 1.092s. DC, DR, HR, SDNN, RMSSD values were lower than that before ablation. AC, SSR, TH values were higher than those before ablation, mean heart rate and the slowest heart rate were significantly increased. There were significant differences in follow-up data between the preoperative and postoperative periods (all p < 0.05). All the patients were successfully ablated, and their blood pressure decreased significantly. No complications such as vascular damage, vascular embolism and pericardial effusion occurred.

CONCLUSIONS

Left Atrial GP ablation has good long-term clinical results and can be used as a treatment option for patients with bradyarrhythmia.

Cardioneuroablation: the known and the unknown

Cardioneuroablation (CNA) is a novel interventional procedure for the treatment of recurrent vasovagal syncope (VVS) and advanced atrioventricular block secondary to hyperactivation of vagal tone in young patients. By damaging the cardiac parasympathetic ganglia, CNA seems to be able to mitigate and/or abolish the excessive vagal activity and improve patients' outcome. This review is intended to give a detailed and comprehensive overview of the current evidences regarding (1) the clinical applications of CNA (2) the identification of ablation targets and procedural endpoints (3) the medium-long term effect of the procedure and its future perspectives. However, clinical data are still limited, and expert consensus or recommendations in the guidelines regarding this technique are still lacking.

Cardioneuroablation in patients with vasovagal syncope: An updated systematic review and meta-analysis

BACKGROUND

Cardioneuroablation (CNA) is a novel procedure that shows promising results in reducing syncope recurrence in patients with refractory vasovagal syncope (VVS). However, its effectiveness and safety remain controversial.

OBJECTIVE

We performed an updated meta-analysis evaluating CNA efficacy and safety in patients with refractory VVS.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for CNA studies in patients with refractory VVS. Our primary efficacy end point was syncope recurrence, and our safety end point was periprocedural complications. Prespecified subgroup analyses were performed for (1) the ganglionated plexus (GP) targeting method and (2) the GP location of ablation.

RESULTS

We included 27 observational studies and 1 randomized controlled trial encompassing 1153 patients with refractory VVS who underwent CNA. The median age was 39.6 years, and follow-up was 21.4 months. The overall weighted rate of syncope recurrence after CNA was 5.94% (95% confidence interval [CI] 3.37%-9.01%; I2 = 64%), and the rate of periprocedural complications was 0.99% (95% CI 0.14%-2.33%; I2 = 0%). Our prespecified subgroup analysis using the GP targeting method and GP ablation location showed a higher prevalence of syncope recurrence in the electroanatomic mapping subgroup (6.21%; 95% CI 2.93%-10.28%; I2 = 0%) and in the right atrium approach (15.78%; 95% CI 3.61%-33.14%; I2 = 65.2%).

CONCLUSION

This study supports the efficacy and safety of CNA in preventing syncope recurrence in patients with VVS. Furthermore, the electroanatomic mapping method of GP targeting and the right atrium approach were associated with a higher syncope recurrence rate than other methods.

Procedural and Intermediate-term Results of the Electroanatomical-guided Cardioneuroablation for the Treatment of Supra-Hisian Second- or Advanced-degree Atrioventricular Block: the PIRECNA multicentre registry

AIMS

Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB.

METHODS AND RESULTS

This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up.

CONCLUSION

This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.

Safety observation of antiarrhythmic drug use in a patient with sinus bradycardia following atrial fibrillation radiofrequency ablation combined with cardiac neural ablation: a case report

This study assessed the safety of Antiarrhythmic Drug (AAD) administration in a patient experiencing sinus bradycardia following radiofrequency ablation for Atrial Fibrillation (AF), followed by cardiac ganglion ablation. Post-AF radiofrequency ablation, the employment of AADs is a prevalent clinical practice; however, these drugs may exacerbate bradycardia, leading to increased patient discomfort and treatment complexity. The decision to employ AADs in patients with sinus bradycardia post-AF ablation poses a significant clinical challenge. This investigation aimed to ascertain the safety of AADs in such patients. The study encompassed a single case, wherein a patient with pre- and post-procedure sinus bradycardia was treated with AADs following AF radiofrequency ablation and cardiac ganglion ablation, with a subsequent safety assessment. The findings indicate that AADs can be safely administered to patients with sinus bradycardia after these procedures, offering valuable insights for clinical decision-making. This case report underscores the intricacies of post-AF ablation management in patients with sinus bradycardia and advocates for personalized therapeutic strategies. The results enhance the clinical knowledge regarding the safety of AADs in this patient subset and may guide future treatment protocols. Nonetheless, the study's conclusions are drawn from a single case, and further research with larger cohorts is essential to substantiate these findings and elucidate the long-term safety and efficacy of this therapeutic approach.

Cardioneuroablation for vasovagal syncope: insights on patients' selection, centre settings, procedural workflow and endpoints-results from an European Heart Rhythm Association survey

AIMS

Cardioneuroablation (CNA) is a catheter-based intervention for recurrent vasovagal syncope (VVS) that consists in the modulation of the parasympathetic cardiac autonomic nervous system. This survey aims to provide a comprehensive overview of current CNA utilization in Europe.

METHODS AND RESULTS

A total of 202 participants from 40 different countries replied to the survey. Half of the respondents have performed a CNA during the last 12 months, reflecting that it is considered a treatment option of a subset of patients. Seventy-one per cent of respondents adopt an approach targeting ganglionated plexuses (GPs) systematically in both the right atrium (RA) and left atrium (LA). The second most common strategy (16%) involves LA GP ablation only after no response following RA ablation. The procedural endpoint is frequently an increase in heart rate. Ganglionated plexus localization predominantly relies on an anatomical approach (90%) and electrogram analysis (59%). Less utilized methods include pre-procedural imaging (20%), high-frequency stimulation (17%), and spectral analysis (10%). Post-CNA, anticoagulation or antiplatelet therapy is prescribed, with only 11% of the respondents discharging patients without such medication. Cardioneuroablation is perceived as effective (80% of respondents) and safe (71% estimated <1% rate of procedure-related complications). Half view CNA emerging as a first-line therapy in the near future.

CONCLUSION

This survey offers a snapshot of the current implementation of CNA in Europe. The results show high expectations for the future of CNA, but important heterogeneity exists regarding indications, procedural workflow, and endpoints of CNA. Ongoing efforts are essential to standardize procedural protocols and peri-procedural patient management.

Cardioneuroablation for Cardioinhibitory Vasovagal Syncope: Rationale, Approaches, and Its Role in Long-Term Management

Purpose of Review

Cardioneuroablation (CNA) has emerged as a potential alternative to pacemaker therapy in well-selected cases with vasovagal syncope (VVS). In recent years, the number of CNA procedures performed by electrophysiologists has considerably risen. However, some important questions, including proper patient selection and long-term results, remain unanswered. The present article aims to critically review and interpret latest scientific evidence for clinical indications and how to approach long-term management.

Recent Findings

CNA is a new approach that has been supported mainly by retrospective or observational data for its use in syncope. Overall, in mixed population studies treated with CNA, 83.3 to 100% have been reported to be free of syncope over follow-up periods of 6 to 52.1 months. For studies including patients who underwent CNA with pure VVS, 73.2 to 100% have been reported to be syncope-free over follow-up periods of 4 to 45.1 months. One large meta-analysis showed 91.9% freedom from syncope after CAN. To date, only one randomized controlled trial with small case number has been performed of CNA compared to non-pharmacological treatment in VVS. In this study of 48 patients with an average of 10 ± 9 spontaneous syncopal episodes prior to study enrollment and 3 ± 2 episodes in the year prior to CNA. After CNA, 92% were free of syncope compared with 46% treated with optimal non-pharmacological treatment to prevent new syncope episodes (P = 0.0004). To date, most studies have included younger patients (< 60 years of age). There are only limited data in patients older than 60, and some studies suggest less of an effect in relatively older patients.

Summary

Cardioneuroablation can be performed to decrease syncope recurrence in adult patients aged < 60 years, with severe or recurrent cardioinhibitory syncope without prodromal symptoms, after proven failure of conventional therapies. Due to a paucity of data supporting efficacy in older individuals or for vasodepressor components, CNA in adult patients aged > 60 years or in the presence of a dominant vasodepressor should be considered investigational in severely symptomatic patients after proven failure of pharmacological and non-pharmacological therapies.

Cardioneuroablation as a strategy to prevent pacemaker implantation in young patients with vasovagal syncope

Background

Cardioneuroablation (CNA) is an ablation technique that targets epicardial ganglionic plexi to reduce syncope burden and avoid pacemaker implantation in patients with cardioinhibitory vasovagal syncope (VVS). This study aims to demonstrate feasibility and safety of CNA in high-risk refractory VVS patients using continuous monitoring with an implantable loop recorder (ILR).

Methods

Data was collected prospectively for patients undergoing CNA. Patients were required to have recurrent syncope with documented asystole, refractory to conservative measures. Ganglionic plexi (GPs) were identified by fragmented signals and high frequency stimulation (HFS). Ablation was performed until loss of positive response to HFS, Wenckebach cycle shortening was achieved, or an increase in sinus rate of > 20 bpm. Follow-up was performed through remote and clinic follow-up of their ILRs.

Results

Between December 2020 and July 2023 six patients (mean age 29 ± 3, 67 % female)underwent CNA. The baseline heart rate and Wenckebach cycle length was 63.2 ± 15 bpm and 582 ms before and 91 ± 5 bpm and 358 ms after ablation respectively. During a median follow-up of 13.4 months, 3/5 patients had no further syncopal episodes, 1 had a recurrence, underwent repeat CNA with no further episodes at 1 year, and 1 had 5 syncopal events, which was a dramatic reduction from nearly daily episodes pre-CNA. There were no procedure related complications.

Conclusions

A dramatic reduction in documented pauses and syncope burden was noted post CNA. Appropriate patient selection with rigorous objective follow-up in an experienced center is necessary. Larger studies are required to confirm these findings.

Potential consequences of cardioneuroablation for vasovagal syncope: A call for appropriately designed, sham-controlled clinical trials

Cardioneuroablation (CNA) is being increasingly used to treat patients with vasovagal syncope (VVS). Bradycardia, in the cardioinhibitory subtype of VVS, results from transient parasympathetic overactivity leading to sinus bradycardia and/or atrioventricular block. By mitigating parasympathetic overactivity, CNA has been shown to improve VVS symptoms in clinical studies with relatively small sample sizes and short follow-up periods (<5 years) at selected centers. However, CNA may potentially tip the autonomic balance to a state of sympathovagal imbalance with attenuation of cardiac parasympathetic activity. A higher heart rate is associated with adverse cardiovascular events and increased mortality in healthy populations without cardiovascular diseases. Chronic sympathovagal imbalance may also affect the pathophysiology of spectra of cardiovascular disorders including atrial and ventricular arrhythmias. This review addresses potential long-term pathophysiological consequences of CNA for VVS.

Cardioneuroablation for pediatric patients with functional sinus node dysfunction and paroxysmal atrioventricular block

INTRODUCTION

Severe transitory episodes of bradycardia with subsequent syncope in children are common, and generally portend a benign prognosis. Rarely, patients may experience prolonged asystolic episodes secondary to significant sinus pauses (SP) or paroxysmal atrioventricular block (AVB). Cardioneuroablation (CNA) is a catheter-based intervention, used to identify and ablate the epicardial ganglionated plexi (GP), which results in disruption of the vagal-mediated parasympathetic input to the sinus and atrioventricular node.

OBJECTIVE

Describe the methodology and role of CNA for treatment of pediatric patients with functional AVB or SP.

METHODS

This is a single-center, case series study. Patients with SP or AVB, 21 years of age or younger, who underwent CNA between 2015 and 2021 were included. CNA was performed via anatomically guided and high-frequency stimulation methods.

RESULTS

Six patients were included. The median age was 18.9 years (range 12.3-20.9 years), 33% female. Two patients had prolonged SP, two had paroxysmal AVB, and two had both SP and AVB. Four patients had prior syncope. The median longest pause was 8.9 s (range 3.9-16.8) with 11 total documented pauses (range 2-231) during the 6 months pre-CNA. Post-CNA, the median longest pause was 1.3 s (range 0.8-2.2) with one documented SP after termination of atrial tachycardia at the 3-month follow-up. At 6 months, the median longest pause was 1.1 s (0.8-1.3) with 0 documented pauses. No patients had syncope post-CNA.

CONCLUSION

CNA may be an effective alternative to pacemaker implantation in pediatric patients with syncope or significant symptoms secondary to functional SP or AVB.

Cardioneuroablation for the Treatment of Vasovagal Syncope: Current Status and Impact on Quality of Life

PURPOSE OF REVIEW

Vasovagal syncope (VVS) is a common entity causing transient loss of consciousness and affecting quality of life. Guideline-recommended therapy involves conservative measures and pacing in selected patients. Cardioneuroablation (CNA) targeting the ganglionated plexi in the heart has been shown to reduce excessive vagal excitation, which plays a major role in the pathophysiology of VVS and functional bradycardia.

RECENT FINDINGS

The introduction of CNA has fueled research into its value for the treatment of VVS. Multiple observational studies and one randomized trial have demonstrated the safety and efficacy of CNA and the positive impact on quality of life. This review describes the rationale and CNA procedural techniques and outcomes. Patient selection and future directions have also been described. Cardioneuroablation is a promising treatment for patients with recurrent VVS and functional bradycardia. Further large-scale randomized studies are needed to further verify the safety and efficacy of this approach.

Endocardial ablation of epicardial ganglionated plexi: history, open questions and future prospects of cardioneuroablation

Neurocardiogenic syncope is the most common cause of transient loss of consciousness and considerably reduces quality of life. Pharmacological and pacing therapy may not be fully efficacious and complications related to implanted hardware must be considered. In this context, cardioneuroablation (CNA) has been proposed to attenuate the vagal reflex with elimination of cardioinhibition. It has been shown that CNA is able to eliminate recurrences of syncope in over 90% of cases and no major complications are reported in the current literature. Despite these encouraging findings, CNA is only mentioned in current guidelines as a possible alternative treatment and has no real indication class. The diversity of mapping techniques, the absence of direct denervation control, the lack of a precise endpoint, the possible placebo effect, the short follow-up, and the question of the learning curve represent the major limitations of this promising procedure. The aim of this review was to look over the existing literature, analysing the novelties, the limitations, the unresolved issues and the outcome of CNA.

Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope

Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation, bradycardia, or both. VVS affects one-third of the population at least once in their lifetime or by the age of 60, reduces the quality of life, and may cause disability affecting certain routines. It poses a considerable economic burden on society, and, despite its prevalence, there is currently no proven pharmacological treatment for preventing VVS. The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope. Several parameters influence the success rate of GP ablation, including specific ablation sites, localization and surgical techniques, method of access, and the integration of other interventions. This review aims to provide an overview of the existing literature on the physiological aspects and clinical effectiveness of GP ablation in the treatment of VVS. Specifically, we explore the association between GPs and VVS and examine the impact of GP ablation procedures as reported in human clinical trials. Our objective is to shed light on the therapeutic significance of GP ablation in eliminating VVS and restoring normal sinus rhythm, particularly among young adults affected by this condition.

Selective anatomical catheter ablation of left atrial ganglionated plexus for vasovagal syncope: Left superior and right anterior ganglionated plexus ablation

BACKGROUND

Vasovagal syncope (VVS) is one of the most common causes of syncope. Traditional treatment has not achieved satisfactory results. The purpose of this study was to assess the feasibility and efficacy of selective anatomical catheter ablation of left atrial ganglionated plexus (GP) as a therapeutic strategy for the patients of symptomatic VVS.

METHODS

A total of 70 patients with at least once recurrent syncopal episode of VVS with a positive head-up tilt test were enrolled. They were divided into GP ablation group and control group. Patients in GP ablation group received anatomical catheter ablation of left superior ganglionated plexus (LSGP) and right anterior ganglionated plexus (RAGP). Patients in the control group were guideline-directed conventional therapy. The primary endpoint was VVS recurrences. The secondary endpoint was the recurrence of syncope and prodrome events.

RESULTS

There were no statistical differences in clinical characteristics between the ablation group (n = 35) and the control group (n = 35). Over a follow-up of 12 months, the ablation group had significantly lower syncope recurrence compared with the control group (5.7% vs. 25.7%, p = .02), and the ablation group had significantly lower syncope and prodrome recurrence compared with the control group (11.4% vs. 51.4%, p < .001). In GP ablation, 88.6% of the patients showed significant vagal response during LSGP ablation, and 88.6% of the patients showed significantly increased heart rate during RAGP ablation.

CONCLUSIONS

For patients with recurrent VVS, selective anatomical catheter ablation of LSGP and RAGP is superior to conventional therapy in reducing syncope recurrence.

Cardioneuroablation for Treating Vasovagal Syncope: Current Status and Future Directions

Syncope is defined by transient and spontaneous loss of consciousness with rapid recovery. Vasovagal syncope (VVS) is the most common form of syncope and is strongly associated with hypervagotonia. There is, however, a lack of effective therapies for VVS. Cardioneuroablation (CNA) is an emerging and promising intervention for VVS with favourable outcomes. CNA has been shown to suppress excessive excitation of vagal activity through ablating the cardiac ganglionated plexi. CNA in the management of VVS requires more structured and comprehensive studies and several issues concerning patient selection, selection of ablation targets, ablation endpoints and the long-term effect of CNA are yet to be determined. This review describes its clinical applications and future directions based on current research data and the authors' own experiences.

Cardioneuroablation Using Epicardial Pulsed Field Ablation for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide. The cardiac autonomic nervous system (ANS) is widely recognized as playing a key role in both the initiation and propagation of AF. This paper reviews the background and development of a unique cardioneuroablation technique for the modulation of the cardiac ANS as a potential treatment for AF. The treatment uses pulsed electric field energy to selectively electroporate ANS structures on the epicardial surface of the heart. Insights from in vitro studies and electric field models are presented as well as data from both pre-clinical and early clinical studies.

Ganglionated plexi ablation in the right atrium for the treatment of cardioinhibitory syncope

Neurocardiogenic syncope, also called vasovagal syncope, represents one of the clinical manifestations of neurally mediated syncopal syndrome. Generally, the prognosis of the cardioinhibitory form of neurocardiogenic syncope is good, but quality of life is seriously compromised in patients who experience severe forms. Drug therapy has not achieved good clinical results and very heterogeneous data come from studies regarding permanent cardiac pacing. In this scenario, the ganglionated plexi ablation has been proposed as an effective and safe method in patients with cardioinhibitory neurocardiogenic syncope, especially in young patients in order to avoid or prolong, as much as possible, the timing of definitive cardiac pacing. Certainly, making this procedure less extensive and limiting the ablation in the right atrium (avoiding the potential complications of a left atrial approach) and at level of anatomical regions of the most important ganglionated plexy, considered 'gateway' of the sino-atrial and atrio-ventricular node function (through the recognition of specific endocardial potentials), could be very advantageous in this clinical scenario. Finally, randomized, multicentre, clinical trials on a large population are needed to better understand which is the best ablation treatment (right-only or bi-atrial) and provide evidence for syncope guidelines.

Intrinsic Cardiac Neuromodulation in the Management of Atrial Fibrillation- A Potential Missing Link?

Atrial fibrillation (AF) is the most common supraventricular arrhythmia that is linked with higher cardiovascular morbidity and mortality. Recent evidence has demonstrated that catheter-based pulmonary vein isolation (PVI) is not only a viable alternative but may be superior to antiarrhythmic drug therapy for long-term freedom from symptomatic AF episodes, a reduction in the arrhythmia burden, and healthcare resource utilization with a similar risk of adverse events. The intrinsic cardiac autonomic nervous system (ANS) has a significant influence on the structural and electrical milieu, and imbalances in the ANS may contribute to the arrhythmogenesis of AF in some individuals. There is now increasing scientific and clinical interest in various aspects of neuromodulation of intrinsic cardiac ANS, including mapping techniques, ablation methods, and patient selection. In the present review, we aimed to summarize and critically appraise the currently available evidence for the neuromodulation of intrinsic cardiac ANS in AF.

Ganglionic Plexus Ablation: A Step-by-step Guide for Electrophysiologists and Review of Modalities for Neuromodulation for the Management of Atrial Fibrillation

As the most common sustained arrhythmia, AF is a complex clinical entity which remains a difficult condition to durably treat in the majority of patients. Over the past few decades, the management of AF has focused mainly on pulmonary vein triggers for its initiation and perpetuation. It is well known that the autonomic nervous system (ANS) has a significant role in the milieu predisposing to the triggers, perpetuators and substrate for AF. Neuromodulation of ANS - ganglionated plexus ablation, vein of Marshall ethanol infusion, transcutaneous tragal stimulation, renal nerve denervation, stellate ganglion block and baroreceptor stimulation - constitute an emerging therapeutic approach for AF. The purpose of this review is to summarise and critically appraise the currently available evidence for neuromodulation modalities in AF.

Permanent pacing versus cardioneuroablation for cardioinhibitory vasovagal syncope

BACKGROUND

We compared the efficacy and safety of cardioneuroablation (CNA) vs. permanent pacing (PM) for recurrent cardioinhibitory vasovagal syncope (CI-VVS).

METHODS

One hundred sixty-two patients (CNA = 61, PM = 101), age 36 + 11 years) with syncope frequency of 6.7 ± 3.9/year were included in this multicenter study. All patients with CNA were provided by a single center, while patients with PM were provided by 4 other centers. In the CNA arm, an electroanatomic mapping guided approach was used to detect and ablate ganglionated plexus sites. Dual chamber rate drop response (RDR) or close loop stimulation (CLS) transvenous and leadless pacemakers were implanted using standard technique. The primary endpoint was freedom from syncope.

RESULTS

Of 101 patients in the PM group, 39 received dual-chamber pacemaker implants with the CLS algorithm, 38 received dual-chamber pacemakers with the RDR algorithm, and 24 received a leadless pacemaker. At 1-year follow-up, 97% and 89% in the CNA and PM group met the primary endpoint (adjusted HR = 0.27, 95% CI 0.06-1.24, p = 0.09). No significant differences in adverse events were noted between groups. There was no significant association between age (HR:1.01, 95% CI 0.96-1.06, p = 0.655), sex (HR:1.15, 95% CI 0.38-3.51, p = 0.809), and syncope frequency in the past year (HR:1.10, 95% CI 0.97-1.25, p = 0.122) and the primary outcome in univariable analyses.

CONCLUSIONS

After adjustment for patient characteristics, the medium-term syncope recurrence risk of CI-VVS patients who underwent CNA was similar to that of a population of patients undergoing pacemaker implantation with a similar safety profile.

Improved health-related quality of life after cardioneuroablation in patients with vasovagal syncope

BACKGROUND

As the most common cause of syncope, vasovagal syncope (VVS) is mediated by parasympathetic overactivity and/or sympathetic withdrawal. Although catheter ablation of ganglionated plexi or cardioneuroablation has been used to treat VVS, its role in quality of life (QoL) has not been formally evaluated. The aim of this study was to demonstrate if this novel treatment results in improvement QoL of patients with VVS.

METHODS

Twenty-seven consecutive patients (age: 34 ± 14 years, 51.8% male) with dominant cardioinhibitory type VVS were prospectively enrolled in the study. After confirmation of > 3 s asystole on head-up tilt testing (HUT), all patients underwent cardioneuroablation. ECGs were obtained prior to procedure and at 12-month follow-up visit. HUTs were repeated 1 month after cardioneuroablation procedures. QoL was assessed with the use of SF-36, EQ-5D, and EQ VAS questionnaires.

RESULTS

ECG, HUT, and QoL data were available in all patients. At 12-month follow-up, heart rate on rest ECG significantly increased (from 74 ± 15 to 84 ± 14 bpm, p = 0.003). Repeated HUTs were negative in 23 (85.1%) patients. All of 27 patients remained free of syncope. QoL assessed by SF-36 score significantly improved in postprocedural follow-up (92 ± 9 and 96 ± 11, p = 0.016). Similarly, significant improvements in mobility, self-care, and usual activity domains of EQ-5D were observed (mean scores of 3.0 ± 1.5 and 2.1 ± 1.3, p < 0.001; 1.3 ± 0.9 and 1.2 ± 0.6, p = 0.041; 1.7 ± 1.0 and 1.4 ± 0.8 respectively). EQ-VAS score also improved significantly (39 ± 24 to 77 ± 18, p < 0.001).

CONCLUSION

Our findings suggest that cardioneuroablation may be associated with intermediate term improvement in QoL in patients with VVS.

Cardioneuroablation for vasovagal syncope: A systematic review and meta-analysis

BACKGROUND

Cardioneuroablation (CNA) has emerged as promising therapy for patients with refractory vasovagal syncope (VVS).

OBJECTIVE

The purpose of this study was to provide a freedom from syncope estimate for CNA, including subgroup analysis by method and target of ablation.

METHODS

A systematic search was performed in MEDLINE and EMBASE according to the PRISMA guidelines until February 14, 2022. Observational studies and clinical trials reporting freedom from syncope were included. Meta-analysis was performed with a random-effects model.

RESULTS

A total of 465 patients were included across 14 studies (mean age 39.8 ± 4.0 year; 53.5% female). Different techniques were used to guide CNA: 50 patients (10.8%) by mapping fractionated electrograms, 73 (15.7%) with the spectral method, 210 (45.2%) with high-frequency stimulation, 73 (15.7%) with a purely anatomically guided method, and 59 (12.6%) with a combination. The target was biatrial in 168 patients (36.1%), left atrium only in 259 (55.7%), and right atrium only in 38 (8.2%). The freedom from syncope was 91.9% (95% confidence interval [CI] 88.1%-94.6%; I2 = 6.9%; P = .376). CNA limited to right atrial ablation was associated with a significant lower freedom from syncope (81.5%; 95% CI 51.9%-94.7%; P <.0001) vs left atrial ablation only (94.0%; 95% CI 88.6%--6.9%) and biatrial ablation (92.7%; 95% CI 86.8%-96.1%). Subgroup analysis according to the technique used to identify ganglionated plexi did not show any significant difference in freedom from syncope (P = .206).

CONCLUSION

This meta-analysis suggests a high freedom from syncope after CNA in VVS. Well-designed, double-blind, multicenter, sham-controlled randomized clinical trials are needed to provide evidence for future guidelines.

The future of cardioneuroablation in cardiovascular medicine

INTRODUCTION

Cardioneuroablation is increasingly being utilized to improve outcomes in patients with vagally mediated bradyarrhythmias. However, there are still controversial issues in the field including patient selection, safety and efficacy, and procedural end-points.

AREAS COVERED

In this review, the current role of cardioneuroablation is summarized, and controversial issues related to the modality are discussed.

EXPERT OPINION

According to small open-label cohort studies, overall freedom from syncope recurrence was higher than 90% after cardioneuroablation in patients with vasovagal syncope (VVS). Use of the electrogram-based strategy or high-frequency stimulation demonstrate similar success rate except in procedures limited to the right atrium. Based on a recently published randomized controlled trial and metanalysis, it may be possible now to make a strong recommendation for cardioneuroablation in patients <40 years of age, and those with the cardioinhibitory or mixed type of VVS who continue to experience frequent and/or burdensome syncope recurrences. Considering patients with VVS are prone to significant placebo/expectation effect, sham-controlled trials may help to quantify the placebo effect. In well-selected patients with functional atrioventricular block and sinus bradycardia, may result in encouraging medium-term outcomes. However, functional bradycardia is identified in a minority of patients presenting with high-grade atrioventricular block or sinus node dysfunction.

Extracardiac Vagal Stimulation-Assisted Cardioneuroablation: Dynamically Evaluating the Impact of Sequential Ganglionated Plexus Ablation on Vagal Control of SAN and AVN in Patients with Sinoatrial Node Dysfunction

Cardioneuroablation (CNA) is proposed as a promising therapy for patients with sinoatrial node dysfunction (SND) that is mediated by excessive vagal tone. However, a series of urgent questions about CNA remain unanswered. From December 2020 to March 2022, six patients with symptomatic SND who underwent CNA were summarized in this report. Sequential CNA targeting Ao-SVC GP, PMLGP, RAGP, and LSGP was performed in patients, guided by fractionated intracardiac electrograms and dynamically evaluated by extracardiac vagal stimulation (ECVS). The results showed that Ao-SVC GP ablation led to a significant increase in heart rate (HR) and the elimination of sinus arrest evoked by ECVS, while the vagal responses of atrial ventricular block were eliminated by the ablation of PMLGP and LSGP. Post-procedure HR increased up to 64-86% of the maximum HR of an atropine test at baseline. The median HR from Holter monitoring increased from 52.8 ± 2.1 bpm at baseline to 73.0 ± 10.4 bpm after the procedure (p = 0.012) and to 71.3 ± 10.1 bpm at the six-month follow-up (p = 0.011). Bradycardia-related symptoms disappeared in all patients at the six-month follow-up. This case series reveals the feasibility of using the ECVS-assisted sequential CNA technique and indicates the critical role of ECVS in dynamically evaluating the impact of sequential CNA on the vagal control of SAN and AVN.

Cardioneuroablation for Vasovagal Syncope and Atrioventricular Block: A Step-by-Step Guide

Catheter based cardioneuroablation is increasingly being utilized to improve outcomes in patients with vasovagal syncope and atrioventricular block due to vagal hyperactivity. There is now increasing convergence amongst enthusiasts on its various aspects, including patient selection, technical steps, and procedural end-points. This pragmatic review aims to take the reader through a step-by-step approach to cardioneuroablation: we begin with a brief overview of the anatomy of intrinsic cardiac autonomic nervous system, before focusing on the indications, pre- and post-procedure management, necessary equipment, and its potential limitations. This article is protected by copyright. All rights reserved.

Comparison of Fragmented Electrogram Based Strategy and High Frequency Stimulation for Detection of Ganglionated Plexi

Ganglionated plexus (GP) ablation is an emerging technique in patients with cardioinhibitory vasovagal syncope and vagally mediated atrial fibrillation. Localization of GPs can be impacted by the technique used. A reproducible methodology for GP detection is needed to account for individual variations during electrophysiologic study. In this article, we aim to compare and contrast high-frequency stimulation vs. a fragmented electrogram guided strategy for GP localization.

Why is the Tilt Table Test Still Useful to Define who Should or Should Not Get A Pacemaker with Vasovagal Syncope?

The the tilt table test (TTT )has been used identify appropriate candidates for pacing in the majority of randomized trials. However, in recent years, it has been claimed-based largely on International Study on Syncope of Uncertain Etiology (ISSUE) studies-that the TTT demonstrates only a weak correlation with the mechanism documented by implantable loop recorder (ILR) at the time of syncope and thus confounds the correct diagnosis. Thus, cardiac pacing was supported in patients with recurrent vasovagal syncope (VVS) in whom clinically relevant asystole had been documented by ILR. In the present Editorial, we tried to discuss potential role of TTT in diagnostic workflow of VVS based on current data.

Management strategies for vasovagal syncope

Vasovagal syncope (VVS) (or neurocardiogenic syncope) is a common clinical condition that is challenging to both physicians and patients alike. Severe episodes of recurrent syncope can result in physical injury as well as psychological distress. This article provides a brief overview of current management strategies and a detailed overview of therapeutic modalities such as closed loop stimulation (CLS) and cardioneuroablation (CNA).

Procedural and short-term results of electroanatomic-mapping-guided ganglionated plexus ablation by first-time operators: A multicenter study

INTRODUCTION

Single-center observational studies have shown promising results with fragmented electrogram (FE)-guided ganglionated plexus (GP) ablation in patients with vagally mediated bradyarrhythmia (VMB). We aimed to compare the acute procedural characteristics during FE-guided GP ablation in patients with VMB performed by first-time operators and those of a single high-volume operator.

METHODS AND RESULTS

This international multicenter cohort study included data collected over 2 years from 16 cardiac hospitals. The primary operators were classified according to their prior GP ablation experience: a single high-volume operator who had performed > 50 GP ablation procedures (Group 1), and operators performing their first GP ablation cases (Group 2). Acute procedural characteristics and syncope recurrence were compared between groups. Forty-seven consecutive patients with VMB who underwent FE-guided GP ablation were enrolled, n = 31 in Group 1 and n = 16 in Group 2. The mean number of ablation points in each GP was comparable between groups. The ratio of positive vagal response during ablation on the left superior GP was higher in Group 1 (90.3% vs. 62.5%, p = .022). Ablation of the right superior GP increased heart rate acutely without any vagal response in 45 (95.7%) cases. The procedure time was longer in group 2 (83.4 ± 21 vs. 118.0 ± 21 min, respectively, p < .001). Over a mean follow-up duration of 8.0 ± 3 months (range 2-24 months), none of the patients suffered from syncope.

CONCLUSION

This multi-center pilot study shows for the first time the feasibility of FE-guided GP ablation across a large group of procedure-naïve operators.

Cardioneuroablation for Treatment of Atrioventricular Block

[Figure: see text].

Clinician needs and perceptions about cardioneuroablation for recurrent vasovagal syncope: An international clinician survey

BACKGROUND

Cardioneuroablation (CNA) targets the intrinsic cardiac autonomic nervous system ganglionated plexi located in the peri-atrial epicardial fat. There is increasing interest in CNA as a treatment of vasovagal syncope (VVS), despite no randomized clinical trial (RCT) data.

OBJECTIVE

The purpose of this study was to poll the opinion on CNA) for VVS.

METHODS

A REDCap (Research Electronic Data Capture) survey was administered to international physicians treating patients with VVS on their opinion about patient selection criteria, ablation approach, RCT design, and most appropriate end points for CNA procedures.

RESULTS

The survey was completed by 118 physicians; 86% were cardiac electrophysiologists. The majority of respondents (79%) would consider referring a patient with refractory VVS for CNA, and 27% have performed CNA for VVS themselves. Most felt patient selection should require a head-up tilt test with a cardioinhibitory response (67%) and suggest a minimum age of 18 years with a median of 3 (interquartile range 2-5) episodes in the past year. There were differences in patient selection between physicians who have performed CNA themselves and those who have not. The majority felt that the ablation strategy should include both atria (70%) with an anatomical approach in combination with autonomic stimulation (85%). Performing a sham procedure in the control arm was supported by 56% of respondents, providing equipoise in RCT design. The preferred primary outcome was freedom from syncope within 1 year of follow-up.

CONCLUSION

There is widespread support for well-designed RCTs to confirm the hypothesized clinical benefit of CNA, provide data to guide the risk-benefit equations during patient selection, and appropriately estimate the placebo effect.

Catheter-Based Cardio-Neural Ablation for Refractory Vasovagal Syncope: First U.S. Report

We highlight the feasibility and efficacy of a new application for catheter ablation to target atrial ganglionated plexi in a patient with refractory vasovagal syncope. We describe a physiologically guided technique and demonstrate 18-month freedom from syncope with 2 tilt-table tests to objectively assess reproducible elimination of symptomatology and underlying pathophysiology. (Level of Difficulty: Beginner.)

Effect of conscious sedation and deep sedation on the vagal response characteristics during ganglionated plexus ablation

INTRODUCTION

We aimed to determine the effects of conscious and deep sedation on vagal response (VR) characteristics during ganglionated plexus (GP) ablation.

METHODS

Forty consecutive patients undergoing GP ablation for vasovagal syncope were divided to receive conscious sedation with midazolam (Group 1, n = 29) or deep sedation with the midazolam-propofol combination (Group 2, n = 11). VR was defined on three levels. R-R interval increase of >50% (Level 1); R-R interval increase of 20%-50% (Level 2); and R-R interval increase of <20% (Level 3).

RESULTS

The ratio of Level 1 VR during ablation on left superior and inferior GPs was significantly lower in Group 2 (p < .0001 and p = .034, respectively). Once the cut-off for VR was decreased to Level 2, the ratio of (+) VR was similar between groups during ablation of left-sided GPs. Positive VR in any level was lower than 20% during ablation of right-sided GPs.

CONCLUSIONS

The autonomic tone might be affected in different ways by the level or type of intravenous sedation. Awareness of anesthesia-related differences may be important if GP ablation will be performed by using VR characteristics during ablation.

Intrinsic cardiac autonomic nervous system: What do clinical electrophysiologists need to know about the "heart brain"?

It is increasingly recognized that the autonomic nervous system (ANS) is a major contributor in many cardiac arrhythmias. Cardiac ANS can be divided into extrinsic and intrinsic parts according to the course of nerve fibers and localization of ganglia and neuron bodies. Although the role of the extrinsic part has historically gained more attention, the intrinsic cardiac ANS may affect cardiac function independently as well as influence the effects of the extrinsic nerves. Catheter-based modulation of the intrinsic cardiac ANS is emerging as a novel therapy for the management of patients with brady and tachyarrhythmias resulting from hyperactive vagal activation. However, the distribution of intrinsic cardiac nerve plexus in the human heart and the functional properties of intrinsic cardiac neural elements remain insufficiently understood. The present review aims to bring the clinical and anatomical elements of the immune effector cell-associated neurotoxicity together, by reviewing neuroanatomical terminologies and physiological functions, to guide the clinical electrophysiologist in the catheter lab and to serve as a reference for further research.

The impacts of the ganglionated plexus ablation sequence on the vagal response, heart rate, and blood pressure during cardioneuroablation

AIMS

Cardioneuroablation is an emerging and promising therapy to treat vasovagal syncope (VVS). The aim of this study was to assess the characteristics of vagal response (VR), heart rate (HR), and blood pressure (BP) during cardioneuroablation with different sequences of ganglionated plexus (GPs) catheter ablation and clarify the regulatory mechanism of cardiac GPs of the left atrium.

METHODS

A total of 28 patients with VVS who underwent cardioneuroablation were prospectively enrolled and randomly assigned to 2 groups according to the ablation order of GPs. Group A: Left superior GP (LSGP) - Left inferior GP (LIGP) - Right inferior GP (RIGP) - Right anterior GP (RAGP); Group B: RAGP - LSGP - LIGP - RIGP.

RESULTS

In Group A, the VR in LSGP, LIGP, RIGP, and RAGP during ablation was observed in 11 (78.6%), 5 (35.7%), 4 (28.6%) and 2 (14.3%) cases, respectively. In contrast, in Group B, the VR in RAGP, LSGP, LIGP, and RIGP was observed in 2 (14.3%), 1 (7.1%), 0 (0%) and 0 (0%) cases, respectively. BP reduction during procedure was observed eight times in Group A and once in Group B (P = 0.013). In both groups, the HR increased significantly during ablation of the RAGP (all P < 0.001).

CONCLUSION

The sequence of GPs ablation during cardioneuroablation affected the occurrence rate of VR and BP reduction during cardioneuroablation. The RAGP was a critical target to increase HR and inhibit VR and BP reduction during procedure, indicating that it may be a key GP in regulation of the cardiac vagal activity.

The anatomical basis behind the neuromodulation effects associated with pulmonary vein isolation

The anatomical basis underlying the neuromodulation effects seen with pulmonary vein (PV) isolation (PVI) is not fully understood. Left atrial (LA) electro-anatomical maps of 38 patients who underwent catheter cardioneuroablation for vagally mediated bradycarrhythmias were studied. During the procedure, LA ganglionic plexi (GPs) were systematically identified and ablated. Design PVI lines were created on these maps by a blinded observer, and the degree of overlap between four GPs and individual PVs was assessed. Here, 1.7 ± 7 (35.5 ± 17.0%) of the total 31.6 ± 10 GP ablation sites per patient were found to overlap with the design PVI lines. The overlap was higher for the right-sided GPs, p < .001. The degree of GP-PV overlap varied: 1 PV in 5 (13.2%) patients, 2 PVs in 15 (39.2%), 3 PVs in 16 (42.1%), and all 4 PVs in 2 (5.3%). No patient had zero GP-PV overlap. A vagal response was most commonly observed during ablation at the left superior GP (89.5%), while a sympathetic response was observed most often during the right superior GP ablation (97.4%). Some degree of GP-PV antral overlap is the norm, and this is more pronounced for the right-sided PVs. There is significant individual variability in the degree of overlap which may explain why neuromodulation effects are not seen universally following PVI.

Effects of permanent cardiac pacing on ventricular repolarization when compared to cardioneuroablation

INTRODUCTION

The impact of cardioneuroablation (CNA) on ventricular repolarization by using corrected QT interval (QTc) measurements has been recently demonstrated. The effects of cardiac pacing (CP) on ventricular repolarization have not been studied in patients with vasovagal syncope (VVS). We sought to compare ventricular repolarization effects of CNA (group 1) with CP (group 2) in patients with VVS.

METHODS

We enrolled 69 patients with age 38 ± 13 years (53.6% male), n = 47 in group 1 and n = 22 in group 2. Clinical diagnosis of cardioinhibitory type was supported by cardiac monitoring or tilt testing. QTc was calculated at baseline (time-1), at 24 h after ablation (time-2), and at 9-12 months (time-3) in the follow-up.

RESULTS

In the group 1, from time-1 to time-2, a significant shortening in QTcFredericia (from 403 ± 27 to 382 ± 27 ms, p < 0.0001), QTcFramingham (from 402 ± 27 to 384 ± 27 ms, p < 0.0001), and QTcHodges (from 405 ± 26 to 388 ± 24 ms, p < 0.0001) was observed which remained lower than baseline in time-3 (373 ± 29, 376 ± 27, and 378 ± 27 ms, respectively). Although the difference between measurements in time-1 and time-2 was not statistically significant for QTcBazett, a significant shortening was detected between time-1 and time-3 (from 408 ± 30 to 394 ± 33, p = 0.005). In the group 2, there was no time-based changes on QTc measurements. In the linear mixed model analysis, the longitudinal reduction tendency in the QTcFredericia and QTcFramingham was more pronounced in group 1.

CONCLUSIONS

Our results demonstrate that CNA reduces QTc levels through neuromodulation effect whereas CP has no effect on ventricular repolarization in patients with VVS.