Cardioneuroablation for the treatment of reflex syncope and functional bradyarrhythmias: A Scientific Statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS) and the Latin American Heart Rhythm Society (LAHRS)

The Efficacy of Left Atrial vs Biatrial Cardioneuroablation in Patients With Vasovagal Syncope: A Randomized Clinical Trial

BACKGROUND

Cardioneuroablation has been proposed to be effective in patients with vasovagal syncope, whereas the preferred ablation strategy is undetermined.

OBJECTIVES

This study aimed to determine the preferred ablation strategy of cardioneuroablation between the left atrial (LA) and the bilateral atrial (BiA) approach.

METHODS

This study was a prospective randomized clinical trial to compare the efficacy of 2 ablation strategies for patients with vasovagal syncope. The participants were randomly assigned to either the LA or BiA ganglion plexus ablation group in a 1:1 ratio.

RESULTS

Eighty participants (37 men [46.2%]; age 38 ±16 years) were enrolled, with 40 participants in each group. The efficacy was 87.5% in the LA group (95% CI: 76.8 to 98.2%) and 90% (95% CI: 80.7 to 99.7%) in the BiA group (P = 0.723; P for noninferiority = 0.001). Compared to the BiA group, LA group reduced the average procedure time by 13 minutes (95% CI: 6-20 minutes), the average x-ray dosage by 5.7 mGy (95% CI: 2.1-9.3 mGy), the average ablation lesions by 4 (95% CI: 2-6), and ablation time by 125 seconds (95% CI: 60-190 seconds). No significant difference was observed in presyncope recurrence rate (15% vs 10%; P = 0.498), quality of life (78.7 ± 13.6 vs 80.9 ± 10.6; P = 0.417), mean heart rate (79 ± 11 vs 77 ± 9; P = 0.391), and response to head-up tilt test (57.1% vs 62.2%; P = 0.664) between groups at 12 months.

CONCLUSIONS

The LA approach's efficacy was noninferior to the BiA approach, whereas the LA approach showed the added benefit of reduced procedure time, a smaller ablation lesion, and smaller x-ray dosage. (Different Catheter Ablation Strategy in Vasovagal Syncope; NCT05573178).

Right atrial cardioneuroablation of asystolic reflex syncope

BACKGROUND

Cardioneuroablation (CNA) should focus on the vagal ganglia located in the right atrium close to the sinoatrial and the atrioventricular nodes.

OBJECTIVE

The study aimed to evaluate the efficacy and safety of right atrial CNA.

METHODS

Patients with severe, asystolic reflex syncope identified by implantable loop recorder (ILR) or tilt testing underwent right atrial CNA and were subsequently monitored using ILR.

RESULTS

The population included 28 patients with a mean age of 40.5 ± 13.4 years, of whom 71% were men. Over a median follow-up period of 12.5 months, 8 patients experienced 44 episodes of asystole lasting longer than 3 seconds, as recorded by an ILR. The burden of asystolic episodes significantly reduced from 0.89 episodes per month before CNA (145 over 163 patient-months) to 0.11 episodes per month after CNA (44 over 397 patient-months), with a relative risk reduction of 0.12, P = .0001. Similarly, the burden of syncopal episodes decreased from 0.23 episodes per month before CNA to 0.06 episodes per month after CNA, resulting in an relative risk reduction of 0.24, P = .0001. Median heart rate increased from 75 bpm (interquartile range: 72-79) before ablation to 83 bpm (interquartile range: 78-85) after ablation, lasting up to 9 months post-procedure. No patients experienced complications during the procedure. During follow-up, 2 patients received pacemakers, 1 underwent a redo procedure, and 4 experienced mild transient symptoms: 3 had palpitations and 1 had dyspnea, none requiring therapy.

CONCLUSION

Right atrial CNA reduced asystolic episodes by 88% and syncopal episodes by 76% during the mid-term follow-up. Adverse events were infrequent and mild.

Translational approach to ventricular innervation: the posterior descending ganglionated plexus

AIMS

Modulation of cardiac neural control is increasingly explored to treat cardiac arrhythmias. While the atrially located ganglionated plexus (GPs) have been studied intensively, characterization of ventricular GPs is sparse. This proof-of-principle study aimed to assess the role of the posterior descending GP (PDGP) for neural control of cardiac electrophysiology, while offering a translational roadmap into clinical practice.

METHODS AND RESULTS

Since an initial systematic literature review revealed the PDGP as a small, consolidated GP on the posterior left ventricle (LV) in dogs, swine, and humans, we subsequently conducted morphological C57BL/6 murine studies (n = 43) indicating ventricular GPs in only 10% of hearts. Based on our initial findings, in a proof-of-principle study analysing 4300 local unipolar electrograms from a multi-electrode sock, the impact of functional PDGP modulation was studied in an ex vivo retrograde-perfused porcine model. Wave propagation characteristics determined by epicardial activation mapping demonstrated increased dispersion of conduction velocity during high-frequency (8.52 ± 2.24 radian vs. 2.79 ± 0.89 radian; P = 0.018) and nicotine stimulation (19.79 ± 6.49 radian vs. 2.79 ± 0.89 radian; P = 0.044) compared to paced rhythm. High-frequency stimulation prolonged activation recovery intervals in the posterior (257.8 ± 6.7 ms vs. 244.8 ± 1.9 ms; P = 0.044) and basal (258.1 ± 4.2 ms vs. 244.8 ± 1.9 ms; P =0.039) right ventricle compared to the posterior LV. Analysis of explanted human hearts confirmed the presence of the PDGP within epicardial adipose tissue near its eponymous coronary artery and the posteromedial left atrial GP. Three-dimensionally reconstructed human hearts suggested the PDGP localization characterized by inter-patient anatomical variability.

CONCLUSION

The present translational approach to ventricular innervation demonstrates first evidence of the functional relevance of the PDGP, with morphological findings indicating species-related differences. Novel imaging modalities might pave the way for future functional and therapeutic interventions.

First experience with a new tool for automatic mapping of fragmented signals in a case report of cardioneuroablation

Cardioneuroablation is a treatment option for patients with recurrent vasovagal syncope (VVS). Ablation targets of parasympathetic ganglionated plexi (GP) adjacent to the right and left atrial walls and distal endocardial inputs of these GP can be identified both by their anatomical localization and by intracardiac mapping of fragmented electrogram signals. In this case of a successful cardioneuroablation of a 22-year-old patient suffering from recurrent VVS, a new algorithm for automatic mapping of fragmented signals (CARTO Elevate Module, Biosense Webster) was used to identify areas of GP. In this first experience, automatic tags of fragmented signals were matching well with anatomically guided ablation points. This new tool for automatic identification of fragmented signals may facilitate and improve cardioneuroablation procedures.

The second Latin American catheter ablation registry ("II LAHRS EP registry")

BACKGROUND

Patient's clinical characteristics, technical resources, center and operator volume, and operator experience and training are known variables impacting outcomes. Although international standards have been agreed to maximize the benefits of this therapy, regional and global differences still exist. Latin American information has not been updated in the last 10 years. This study aimed to analyze current information on operators, centers, and CA in Latin America.

METHODS

Observational, retrospective study collecting Latin American information on operators and centers participating in CA, and procedures performed in 2023, from January 1 to December 31.

RESULTS

Electrophysiologists 178 (18 countries). Mean age 46,8 ± 9,2 (28-74) years. Male 86,5%. AFib, VT, and cardioneuroablation were performed by 80,2%, 70,9%, and 35,5% of operators respectively. Centers 175 (17 countries). Private 79,4% and academic 44,0%. Low volume (< 50/year) represented 36,6% and 38,3% performed ≥ 100 ablations/year. Procedures 7.595 (8.284 arrhythmias, 17 countries, 134 centers, 76 electrophysiologists). Patients mean age 51,5 ± 19,3 (1-95) years, male 55,3%, and 77,5% had a structurally normal heart. RF was the energy in 95,6% of procedures, cryoablation in 4,7%, and PFA in 0,2%. The most frequently treated arrhythmias were AFib (28,2%), AVNRT (20,9%), APs (15,8%), and PVC/NSVT (8,3%). Global success and complication rates were 93,6% and 3,0%, respectively and mortality 0,05%.

CONCLUSION

II LAHRS EP Registry brings new and interesting data related to EP in Latin America. Electrophysiologists showed acceptable levels of experience, skills, and qualification. Although centers revealed an under-ideal availability of infrastructure and technical resources, the results of CA were comparable to other registries worldwide.

Cardiac Neuromodulation and Neurocardiology

Neurocardiology has mostly been a specialty of medicine led by anatomists and physiologists. The characterization of the cardiac autonomic nervous system has resulted in a new understanding and appreciation of neurocardiology, leading to potential novel neuromodulation therapies in clinical cardiology and cardiac electrophysiology. Sympathectomy or spinal cord stimulation for the treatment of angina pectoris, as well as cardiac sympathetic denervation for the treatment of long QT syndrome associated with malignant ventricular arrhythmias, have been available and performed for more than half a century. However, a new neuromodulation has emerged, based on contemporary research findings, assisted by state-of-the art imaging and ablation techniques. Patients with structural heart disease and malignant ventricular arrhythmias, as well as symptomatic ventricular ectopy, can potentially benefit from techniques to reduce autonomic tone, such as stellate ganglionic block, epidural anesthesia and cardiac sympathetic denervation. Renal sympathetic denervation not only has been shown to ameliorate the treatment of patients with hypertension, but may also reduce atrial and ventricular arrhythmias. Patients with heart failure may be improved clinically by potentiating parasympathetic tone. Cardiac mapping of ganglia and nerves can be performed to delineate regions of ablation that can suppress atrial fibrillation, and potentially treat symptomatic bradyarrhythmias and cardio-inhibitory syncope.

Endocardial gaglionated plexi ablation in different vagally-mediated clinical settings: From cardioneuroablation to cardio-neuromodulation

Cardioneuroablation (CNA) is now recognized as a safe and effective method in patients with cardioinhibitory neurocardiogenic syncope (CNCS), especially in young patients in order to avoid or prolong, as much as possible, the timing of definitive cardiac pacing. Several investigations have shown beneficial and very satisfactory results with a standard non-extensive endocardial ablation, aimed at identifying high-amplitude fragmented signals in the right and left atria. Despite this, the current scientific debate is focused about a proposal on an ablative method, even more individualized than CNA (at least as a first approach), considering that a standardized approach, especially in the left atrium, could expose CNCS patients with a good prognosis to an excessive risk of complications. These findings, moving from the concept of CNA to a new concept of 'cardioneuromodulation', opened a new era, aimed at a non-extensive and individualized treatment of different clinical CNCS scenarios or vagally-mediated atrioventricular block or sinus-atrial node dysfunction.

Cardioneuroablation in the Management of Vagally Mediated Bradyarrhythmias-A Comprehensive Review of Ongoing Randomized Controlled Trials

Cardioneuroablation is a rapidly developing procedure for the treatment of vagally mediated bradyarrhythmias. However, the lack of multicenter, randomized trials prevents it from being included in bradyarrhythmia treatment guidelines. So far, only one small, randomized study has been published assessing the effectiveness of this method in the treatment of reflex syncope. This is a brief review of ongoing randomized trials evaluating the effectiveness and safety of cardioneuroablation for the treatment of functional bradyarrhythmias.

Cardioneuroablation for reflex syncope or functional bradyarrhytmias: new insight from a single center experience

Background

Cardioneuroablation (CNA) is a new approach to treat reflex syncope and functional bradyarrhytmias caused by autonomic imbalance. We report our experience using CNA.

Method

From September 2022 to July 2023, we took care of 21 patients (mean age 42 ± 21 years; 62% male) affected by reflex syncope or functional bradyarrhythmias. All patients underwent CNA under conscious sedation targeting the superior and/or inferior paraseptal ganglionated plexus (GPs).

Results

Nine patients were affected by vasovagal syncope (VVS) and twelve by functional bradyarrhythmias. In 3 cases (14%) the ablation was performed only on the GPs of the right atrium, while in the remaining 86% of cases we performed biatrial lesions. As regards the acute results, we highlighted an increase in sinus heart rate (12 ± 15 bpm, p = 0.001), a shortening of the PQ interval (-18 ± 18 msec, p < 0.001), a reduction of the correct sinus node recovery times (cSNRT) (-142 ± 204 msec, p = 0.114), a shortening of the AH interval (-31 ± 26 msec, p = 0.008), a reduction of the effective refractory period of the atrio-ventricular node (-156; interquartile range from -30 to -160 msec, p = 0.042) and an increase in the Wencheback point (27 ± 20 bpm, p < 0.001). At follow-up, a single patient, due to persistent symptoms and bradyarrhythmic disorder, underwent permanent pacemaker implantation; no other patient had recurrence of syncope, and all remained persistently asymptomatic.

Conclusion

Our results confirm the efficacy and safety of CNA for the treatment of VVS and functional bradyarrhythmias, although further studies are needed to support these findings.

Cardioneuroablation for the Treatment of Vasovagal Syncope Induced by Chili Pepper Stimulation: A Case Report

A 60-year-old woman was admitted to the hospital with "repeated loss of consciousness for 20 years." An electrocardiogram performed revealed sinus rhythm, and echocardiography, head/chest CTs, and a laboratory examination yielded no significant abnormalities. Besides, there were no positive results from the head-up tilt test. The subsequent decrease in heart rate and blood pressure following the ingestion of chili pepper indicated a potential case of vasovagal syncope(VVS) with cardioinhibition. Following cardioneuroablation, there was an observed increase in heart rate compared to pre-procedure levels. Furthermore, no recurrence of similar symptoms was reported during the one-year follow-up period.