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).

Cardioneuroablation has emerged as a potential alternative to cardiac pacing in selected cases with vasovagal reflex syncope, extrinsic vagally induced sinus bradycardia-arrest or atrioventricular block. The technique was first introduced decades ago, and its use has risen over the past decade. However, as with any intervention, proper patient selection and technique are a prerequisite for a safe and effective use of cardioneuroablation therapy. This document aims to review and interpret available scientific evidence and provide a summary position on the topic.

Long-term outcomes of cardioneuroablation with and without extra-cardiac vagal stimulation confirmation in severe cardioinhibitory neurocardiogenic syncope.

BACKGROUND: Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra-cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA. OBJECTIVE: This study aimed to compare the long-term follow-up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS. METHOD: A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1 ± 2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing. RESULTS: Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow-up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9 ± 20 months for the NoECVS group (p = .24). Notably, syncope recurrence was significantly lower in the ECVS group (two cases vs. four cases, Log Rank p = .04). Moreover, the Hazard ratio revealed a fivefold higher risk of syncope recurrence in the NoECVS group. CONCLUSION: This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation.

Effect of dexmedetomidine added to retrobulbar blockade with lignocaine and bupivacaine in dogs undergoing enucleation surgery.

OBJECTIVE: To investigate the effect of the addition of dexmedetomidine (BLD) to retrobulbar blockade with combined lignocaine and bupivacaine on nociception. ANIMALS: A total of 17 eyes from 15 dogs. METHODS: Prospective, randomized, masked clinical comparison study. Dogs undergoing unilateral enucleation were randomly assigned into two groups; a retrobulbar administration of lignocaine and bupivacaine in a 1:2 volume ratio combined with either BLD or 0.9% saline (BLS). The total volume of the intraconal injection was calculated at 0.1 mL/cm cranial length. Intraoperative parameters were recorded: heart rate (HR), respiratory rate (RR), end-tidal CO2 (EtCO2 ) arterial blood pressure (BP), and inspired isoflurane concentration (ISOinsp). Pain scores, heart rate and RR were recorded postoperatively. RESULTS: Dogs receiving BLD (n = 8) had significantly lower intraoperative RR (p = 0.007), and significantly lower ISOinsp (p = 0.037) than dogs in the BLS group (n = 9). Postoperatively heart rate was significantly lower in the BLD group at 1 min (p = 0.025) and 1 h (p = 0.022). There were no other significant differences in intraoperative or postoperative parameters, or in postoperative pain scores (p = 0.354). Dogs receiving BLD had a higher rate of anesthetic events of bradycardia and hypertension (p = 0.027). Analgesic rescue was not needed in either group. CONCLUSIONS: The addition of BLD to retrobulbar anesthesia did not result in a detectable difference in pain scores relative to blockade with lignocaine and bupivacaine alone. Dogs receiving retrobulbar BLD had a significantly lower intraoperative RR and isoflurane requirement and an increased incidence of intraoperative bradycardia and hypertension.

Clinical impact of aging on outcomes of cardioneuroablation for reflex syncope or functional bradycardia: Results from the cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs-The ELEGANCE multicenter study.

BACKGROUND: Cardioneuroablation (CNA) is a novel treatment for reflex syncope. The effect of aging on CNA efficacy is not fully understood. OBJECTIVE: The purpose of this study was to assess the impact of aging on candidacy and efficacy of CNA for treating vasovagal syncope (VVS), carotid sinus syndrome (CSS), and functional bradyarrhythmia. METHODS: The ELEGANCE (cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs) multicenter study assessed CNA in patients with reflex syncope or severe functional bradyarrhythmia. Patients underwent pre-CNA Holter electrocardiography (ECG), head-up tilt testing (HUT), and electrophysiological study. CNA candidacy and efficacy was assessed in 14 young (18-40 years), 26 middle-aged (41-60 years), and 20 older (>60 years) patients. RESULTS: Sixty patients (37 men; mean age 51 ± 16 years) underwent CNA. The majority (80%) had VVS, 8% had CSS, and 12% had functional bradycardia/atrioventricular block. Pre-CNA Holter ECG, HUT, and electrophysiological findings did not differ across age groups. Acute CNA success was 93%, without differences between age groups (P = .42). Post-CNA HUT response was negative in 53%, vasodepressor in 38%, cardioinhibitory in 7%, and mixed in 2%, without differences across age groups (P = .59). At follow-up (8 months, interquartile range 4-15), 53 patients (88%) were free of symptoms. Kaplan-Meier curves did not show differences in event-free survival between age groups (P = .29). The negative predictive value of a negative HUT was 91.7%. CONCLUSION: CNA is a viable treatment for reflex syncope and functional bradyarrhythmia in all ages, and is highly effective in mixed VVS. HUT is a key step in postablation clinical assessment.

Bradyarrhythmia in a marathonist: Cardiac vagal denervation as alternative treatment.

Although not routinely used, cardioneuroablation or modulation of the cardiac autonomic nervous system has been proposed as an alternative approach to treat young individuals with enhanced vagal tone and significant atrioventricular (AV) disturbances. We report the case of a 42-year-old athlete with prolonged ventricular pauses associated with sinus bradycardia and paroxysmal episodes of AV block (maximum of 6.6 s) due to enhanced vagal tone who was admitted to our hospital for pacemaker implantation. Cardiac magnetic resonance and stress test were normal. Although he was asymptomatic, safety concerns regarding possible neurological damage and sudden cardiac death were raised, and he accordingly underwent electrophysiological study (EPS) and cardiac autonomic denervation. Mapping and ablation were anatomically guided and radiofrequency pulses were delivered at empirical sites of ganglionated plexi. Modulation of the parasympathetic system was confirmed through changes in heart rate and AV nodal conduction properties associated with a negative cardiac response to atropine administration. After a follow-up of nine months, follow-up 24-hour Holter revealed an increase in mean heart rate and no AV disturbances, with rare non-significant ventricular pauses, suggesting that this technique may become a safe and efficient procedure in this group of patients.

Dexmedetomidine for sedation during epicardial ablation for ventricular tachycardia: a single-center experience.

BACKGROUND: Epicardial approach to ventricular tachycardia (VT) ablation is mainly performed under general anesthesia (GA). Although catheter manipulation and ablation in the epicardial space could be painful, GA lowers blood pressure and may interfere with arrhythmia induction and mapping, and the use of muscle relaxants precludes identification of the phrenic nerve (PN). Moreover, an anesthesiologist's presence is required during GA for the whole procedure, which may not always be possible. Therefore, we evaluated the feasibility and safety of epicardial VT ablations performed under conscious sedation using dexmedetomidine in our center. METHODS: Between January 2018 and January 2022, all patients who underwent epicardial VT ablation under continuous dexmedetomidine infusion were prospectively included in the study. All patients received premedication 30 min before the epicardial puncture with paracetamol (acetaminophen 10 mg/ml) 1000 mg and ketorolac 30 mg. Sedation protocol included an intravenous bolus of midazolam hydrochloride (0.03-0.05 mg/kg) followed by continuous infusion of dexmedetomidine (0.2-0.7 mcg/kg/h). In addition, an intravenous fentanyl citrate bolus (0.7-1.4 mcg/kg) was given for short-term analgesia, followed by a second dose repeated after 30 to 45 min. Sedation-related complications were defined in case of respiratory failure, severe hypotension, and bradycardia requiring treatment. RESULTS: Sixty-nine patients underwent epicardial or endo-epi VT ablation under conscious sedation and were included in the analysis. The mean age was 65.4 ± 12.1 years; forty-six patients were males (66.6%). All patients had drug-refractory recurrent VT. Forty-seven patients (68.1%) had non-ischemic cardiomyopathy (NICM), 13 patients (18.9%) had ischemic-cardiomyopathy (ICM), and 9 patients (13%) had myocarditis. Standard percutaneous sub-xiphoid access was attempted in all patients. Non-inducibility of any VT was achieved in 82.6% (9/9 myocarditis, 10/13 ICM, 38/47 NICM, n = 57/69 patients), inducibility of non-clinical VT in 13% (3/13 ICM, 6/38 NICM, n = 9/69 patients), and failure in 4.3% (3/38 NICM, n = 3/69 patients). Although we observed procedural-related complications in five patients (7.2%), one transient PN palsy, two pericarditis, and two vascular complications, those were not related to the conscious sedation protocol. No respiratory failure, severe hypotension, or bradycardia requiring treatment has been observed among the patients. CONCLUSIONS: Prompt availability of anesthesiology support remains crucial for complex procedures such as epicardial VT ablation. Continuous infusion of dexmedetomidine and administration of midazolam and fentanyl seem to be a safe and effective sedation protocol in patients undergoing epicardial VT ablation.

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.

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.

The Importance of Selecting Permanent Pacemaker, Evaluating the Heart and Assessing Quality of Life in Cardiac Patient.

The use of pacemakers is necessary for patients with symptomatic bradycardia. Pacemaker implantation also acts as a life-saving procedure. However, there are several reports that patients with a pacemaker (the most widely used pacemaker is on the right ventricle, known as single chamber pacemaker) had disturbances in left ventricle contraction lead to left ventricular systolic dysfunction. Global Longitudinal Strain (GLS) Echocardiography can confirm these left ventricular disturbances. Echocardiography examination is best carried out before and after single-chamber PPM implantation. This study compares PPM placement in apical Right Ventricle (RV) and Right Ventricular Outflow Tract (RVOT) and compares paced QRS duration 150 ms and > 150 ms. Pacing burden >40% causes subclinical left ventricular systolic dysfunction after a month of PPM implantation with decreased GLS in apical RV pacing.This study gives additional information that PPM placement is preferably in RVOT with some specific settings. However, there are many ways to reduce the effects of impaired left ventricular function due to lead installation on the PPM single-chamber device. By using the PPM device which has a dual chamber, the leads will be placed in RVOT and also in the right atrium with atrial-ventricle synchronization. The aim is to avoid impaired left ventricular pump function as supported by a systematic review which states the superiority of dual-chamber PPM over single-chamber PPM in reducing atrial fibrillation and pacemaker syndrome. In the importance of quality of life related to heart disease, the Indonesian version of the MacNew questionnaire can be used. This questionnaire seeks the quality of life of patients with coronary heart disease after revascularization surgery and has undergone rehabilitation. Another important thing is the suitability of the adaptation to the original English version.

Medium-term results of cardioneuroablation for clinical bradyarrhythmias and vasovagal syncope: effects on QT interval and heart rate.

PURPOSE: Although parasympathetic effects of cardioneuroablation (CNA) in vagally mediated bradyarrhythmias (VMB) were studied, sympathetic effects have not been elucidated, yet. We aimed to investigate the acute and medium-term outcomes of CNA as well as the impact of CNA on ventricular repolarization by using corrected QT interval (QTc) measurements. METHODS: Sixty-five patients (58.5% men; age 39.4 ± 14 years) undergoing CNA were included in the study. Patients who underwent CNA due to VMB were divided into two groups: (1) bi-atrial CNA and (2) right-sided CNA. QTc was calculated at 3 time points: before the procedure (time point 1); 24 h post-ablation (time point 2); and at the last follow-up visit (time point 3). RESULTS: The mean follow-up time was 20.0 ± 20 months. Acute success was achieved in 64 (98.4%) of cases. In the whole cohort, from time point 1 to 2, a significant shortening in QTcFredericia, QTcFramingham, and QTcHodges was observed which remained lower than baseline in time point 3. Although the difference between measurements in time point 1 and 2 was not statistically significant for QTcBazett, a significant shortening was detected between time point 1 and 3. There was significant difference between groups for shortening in QTcFredericia and QTcFramingham (p = 0.01). Event-free survival was detected in 90.7% (59/65) of cases. CONCLUSIONS: Our results demonstrate a significant shortening of QTc in addition to high acute and medium-term success rates after CNA. The most likely mechanism is the effect of CNA on the sympathetic system as well as on the parasympathetic system. Bi-atrial ablation was found related to higher QTc shortening effect.

False Asystole Alarms Post-Temporary Pacemaker Placement Due to Pseudo-fusion.

An infant with congenital heart block and hemodynamically significant bradycardia underwent therapeutic temporary pacing wires placement. Post-operatively, frequent "asystole" alarms were observed on telemetry causing distress to both the family and the nursing staff. Investigation of these alarms showed that pacemaker malfunction led to monitor pseudo-malfunction. The alarms were alleviated with mindful setting of the pacemaker and telemetry monitor parameters. This case highlights the challenges of pacemaker placement and monitoring of very small infants in the intensive care setting. Awareness of these challenges would help in troubleshooting pacemaker and telemetry monitor issues.

Early experience with permanent pacemaker implantation at a tertiary hospital in Nigeria.

INTRODUCTION: artificial pacemakers generate electrical impulses and regulate the heart´s conduction system. They are often used to treat individuals with bradycardia. Permanent pacemaker implantation is a lifesaving procedure especially in patients with symptomatic bradyarrhythmias. The objectives was to evaluate the clinical attributes and outcomes of permanent pacemaker implantation in Ile-ife, Nigeria. METHODS: we retrospectively reviewed medical records of 22 patients who had pacemaker implantation from January 2015 to December 2019. Patient´s demographics, clinical presentation, diagnosis, comorbidities, type of device, complications and long-term follow up were studied. RESULTS: sixteen males (72.7%) and 6 females (27.3%) were recruited into the study with ages ranging between 54 and 84 years and a mean of 70.3 +8.7 years. The commonest symptom was easy fatigability (45.5%) followed by syncope (31.8%). The main indication for permanent pacemaker implantation was complete heart block (86.4%). Seventeen (77.3%) patients had hypertension as the comorbidity present at diagnosis. Single chamber (VVIR) pacemaker was implanted in 13(59.1%) patients while dual chamber (DDDR) was implanted in 9(40.9%) patients. Hematoma, pneumothorax and acute lead dislodgement were the complications observed in 3 patients. There was no statistical significance between the type of device implanted and the occurrence of complications, p-value 0. 186. There was no mortality and 15 patients (68.2%) are currently attending regular 6 monthly follow-up. CONCLUSION: complete heart block is the most common indication for permanent pacemaker implantation and the procedure is safe with minimal complications and satisfactory outcomes.

Successful leadless pacemaker implantation in a patient with profound bradycardia following transcatheter aortic valve replacement and mitral valve-in-valve procedure.

Leadless pacemakers provide a potential alternative to conventional transvenous pacemakers for patients undergoing high-risk transcatheter valve replacement procedures. This is a description of a successful leadless pacemaker implantation in a 51-year-old woman who developed profound bradycardia following a transcatheter aortic valve replacement and mitral valve-in-valve procedure.

Why is pulmonary vein isolation not enough for vagal denervation in all cases?

Pulmonary vein isolation (PVI) may cause vagal response during radiofrequency application or increase on heart rate after ablation. All those responses are related to inadvertent ablation effect on ganglionated plexi. In the present case, we aimed to explain why vagal response effects of PVI are not same in all cases.

Long-term effect of catheter ablation on tachycardia-bradycardia syndrome: evidenced by 10 years follow up.

Background: Catheter ablation has been used for the treatment of tachycardia-bradycardia syndrome (TBS). However, data on its long-term effect of rhythm control and stroke are limited.Method and results: Patients with TBS admitted in the First Affiliated Hospital of Dalian Medical University from 2002 to 2013 were reviewed in the present study. A total of 150 patients were enrolled. Seventy-nine patients underwent catheter ablation (CA group) and 71 patients chose implantation of pacemaker (PM group). The two groups were followed up for 123.01 ± 29.68 and 120.67 ± 31.05 months respectively. The CA group underwent 1.2 ± 0.5 procedure. Of the CA group, 70.9% patients exhibited sinus rhythm without long pauses or the need of anti-arrhythmia drugs (AADs). In contrast, no patient in the PM group was free of atrial fibrillation (AF). A higher proportion in the PM group progressed to persistent AF than in that in the CA group (9.9% vs. 1.3%, p < .05). The incidence of new-onset stroke in the PM group was significantly higher than that in the CA group (15.4% vs. 5.1%, p < .05).Conclusions: Even for long-term following up, catheter ablation is effective for preventing both the tachycardia and bradycardia components for the majority of patients with TBS without the need for further pacemaker implantation. Furthermore, ablation can reduce the stroke incidence of TBS through eliminating AF and reducing the progression to persistent AF.