Active clinical trials for "Syncope, Vasovagal"

Introduction. Reflex vaso-vagal syncope (VVS) is the most frequent cause of transient loss of consciousness and it's treatment remains a challenge. Cardioneuroablation (CNA) is a relatively new and promising method, however, the optimal technique for performing CNA has not been established. Aim. To compare effectiveness of CNA performed in the right atrium (RA) versus left atrium (LA) in achieving total vagal denervation and in preventing syncope recurrences. Methods. Study group. Consecutive patients with recurrent cardioinhibitory or mixed VVS, undergoing CNA between January 2022 and February 2024 will be randomized to the RA or LA groups. CNA is performed under general anesthesia with muscle relaxation using a 3.5 mm irrigated tip contact force catheter and ablation index.The whole procedure is performed under intracardiac echocardiography (ICE) guidance. Efficacy of vagal denervation is assessed using extracardiac vagal stimulation (ECVS). Before starting RF delivery baseline electrophysiological parameters are measured. Next, baseline ECVS from the left and right jugular veins is performed. In the LA group, after gaining transseptal access under ICE guidance, an electroanatomical map of the LA is created and anatomically-based ablation of GP from the LA is performed. Firstly, septal GP are ablated and if total vagal denervation is not achieved, GP located close to left pulmonary veins are ablated. If ECVS still shows vagal response, additional RF applications are delivered in the RA. Then, final ECVS is performed and procedure is finished. In the RA group, GP located in this chamber are ablated and if ECVS shows persistent vagal response, transseptal puncture is performed and ablation in the LA is performed. Afterwards, final ECVS is performed. Duration of follow-up is two years. Patients will attend check-up visits at 3, 12 and 24 months with standard ECG, 24hr ambulatory ECG and QoL assessment. Primary endpoint is complete vagal denervation measured by ECVS (no sinus arrest and no AVB after CNA) using LA approach only versus RA approach only Secondary endpoints include final ECVS results and follow-up data - syncope/presyncope recurrences and QoL.

This is a prospective, international multi-center, open-labeled, randomized trial. The investigator speculated that CNA prevents more patients with moderate to severe VVS from syncope recurrence compared to midodrine.

Syncope, a sudden, transient loss of consciousness (TLOC), is a common inconvenience of daily function and quality of life (QoL). The vasovagal syncope (VVS) is the most common type of syncope, which central and peripheral stimuli may trigger syncope by decreasing peripheral vascular resistance, bradycardia, or both. The venous return to the heart is one of these triggers which its reduction may occur due to prolonged standing, hot environment, hypovolemia, or redistribution of blood volume. The compression stockings may reduce syncopal episodes by increasing venous return. Although the use of compression stockings was never assessed in clinical trials, it could be a possible treatment for decreasing VVS recurrences.

The investigators are interested in whether discrete counterpressure maneuvers, or muscle movements in the lower body, will boost blood pressure and cardiovascular control in children who faint. We will record cardiovascular responses to maneuvers of exaggerated sway, leg crossing, crouching, and gluteal muscle tensing in children who faint (N=20), as well as their height, weight, muscularity, and pubertal (Tanner) stage. Autonomic cardiovascular control will be measured using a Valsalva manoeuvre (expiration against a closed airway for 20 seconds) and a supine-stand test. The primary outcomes are noninvasive measures of cardiovascular responses to the maneuvers (blood pressure, cerebral blood flow, and stroke volume (volume of blood pumped per heartbeat). Comparisons will be made across levels of sex, diagnosis, Tanner stage, muscularity, height, and degree of autonomic control.

Background: Reflex syncope is a disease of benign etiology but in severe cases it can be disabling and it carries a risk of severe trauma. Today, there is no proven etiological treatment and only palliative treatments are used, namely a change in hygienic and dietary habits, certain drugs or, in the most severe cases, the implantation of a pacemaker. Cardioneuroablation is a novel technique that acts by ablating the parasympathetic ganglia located on the external walls of the atria. Several prospective series with promising results have been published, but there are no randomized studies that have validated its efficacy compared to conventional treatment. Methods: The CARDIOSYRE study is a multicenter, randomized, single-blinded study of patients with reflex syncope. The aim is to recruit, between June 2022 and June 2025, 92 patients with reflex cardioinhibitory syncope in 15 centers and randomize them (1:1 ratio) to two treatment groups: 1) cardioneuroablation intervention; 2) conventional treatment (control group). The primary end-point will be the time to the first syncope and the secondary end-point will be the total incidence of syncope after one year of follow-up. At least 20 recurrences of syncope are expected during a 1-year follow-up. A relative risk of 0.3 and a statistical power of 80% are assumed. The follow-up will be carried out at 3, 6 and 12 months. Cox models will be used to estimate adjusted Hazard ratios.

The investigators will assess the efficacy of clinically recommended counterpressure maneuvers (CPM) in preventing syncope for paediatric patients. Participants presenting to the emergency department (ED) will first provide written informed consent. In stage I, they will be asked to complete a brief survey documenting the presentation of their syncopal episode, and any prodromal symptoms they experienced. Participants that consent to the second stage of the study will either receive usual care (control arm) or training in counter pressure maneuvers alongside usual care (intervention arm; leg crossing, bending, arm tensing). These patients will be followed for one years time, and will be asked to complete monthly surveys detailing their syncopal and presyncopal recurrence. Medical records will be accessed over the duration of the study to identify any changes in medical diagnosis.

Project rationale: Vasovagal syncope (VVS) affects up to 50% of people, and recurrent syncope markedly reduces quality of life. We recently reported that it is frequently associated with injury and not surprisingly with clinical anxiety. Although conservative measures help many patients there remain many who require more care. CIHR-funded studies have shown that fludrocortisone and midodrine are effective but cannot be used in patients with contraindications such as hypertension and heart failure. Pacemakers are partially effective in older patients, but this is established only in the small minority with proven asystole. There remains a need for a simple, once-daily medication with few contraindications that can be used as first-line therapy for most patients with recurrent vasovagal syncope. Preliminary Studies: Norepinephrine transport (NET) inhibitors show promise as a novel treatment. Three (reboxetine, sibutramine, and atomoxetine) all prevent vasovagal syncope in healthy subjects and vasovagal syncope patients on tilt tests. Atomoxetine, approved to treat attention deficit disorder, is a highly selective NET inhibitor. We reported a proof-of-principle, randomized, placebo-controlled trial of the efficacy of atomoxetine to prevent vasovagal syncope on tilt table tests. Patients underwent tilt testing after receiving either atomoxetine 40 mg or placebo. Fewer VVS patients fainted with atomoxetine than placebo (10/29 vs. 19/27; odds ratio 0.22, p < 0.01). Our meta-analysis of the effects of NET inhibition on the vasovagal reflex induced by tilt tests was highly positive. A pre-post study showed that sibutramine reduced syncope frequency in highly symptomatic and drug-refractory patients. A similar pre-post study showed that atomoxetine also reduces syncope frequency about 85% in patients with frequent and drug-intolerant or drug-resistant vasovagal syncope. Therefore,NET inhibition by atomoxetine merits assessment based on positive proof-of-principle studies, an apparent class effect, and two open-label pre-post studies. These results provide the rationale for a formal randomized, placebo-controlled, crossover trial of atomoxetine in moderate-to-high risk patients with VVS. Hypothesis: We will test the hypothesis that oral atomoxetine prevents syncope in patients with recurrent VVS. The Study: Patients will be included based on a positive Calgary Syncope Symptom Score and a history of at least 2 faints in the previous year. Eligible patients will be randomized to atomoxetine 40 mg po twice daily or matching placebo in a randomized, placebo-controlled, parallel design, double-blind, crossover trial. Each arm will last 6 months with a 1-week washout period. The primary outcome measure will be the proportion of patients with at least 1 syncope recurrence. The study will be powered to detect a beneficial odds ratio of 0.5, selected on the basis of the control outcome rates in 2 similarly designed, previous studies and international expert requirements for effect size. A sample size of 180 subjects will provide 85% power of detecting a difference between the arms at p<0.05. We will assess the effects of atomoxetine on quality of life, anxiety, injury, and the cost-effectiveness of atomoxetine treatment, and the effects of genetic factors on outcomes. Substudies : The quality of life scales will be the SF-36 and the Euroqol EQ5D, which will also be used as the health utility index for the economic studies. The depression and anxiety scales will be the Hospital and Anxiety Depression Score (HADS) and the General Anxiety Disorder - 7 Score (GAD-7). Clinical anxiety is highly prevalent in patients with recurrent syncope. Injury will be self-reported using our published definitions. The health economic substudy will be from the health system perspective and will use Alberta administrative data. DNA will be collected from spit acquired in the Oragene saliva self-collection kits, and an initial candidate gene study might include alleles of CYP2D6, COMT, the serotonin (SLC6A4) and norepinephrine (SLC6A2) reuptake transporters, and the 5HT1A and 5HT3 receptors. Summary: Adults who faint recurrently are highly symptomatic. There are no therapies suitable for most patients have withstood the test of randomized clinical trials. If successful, atomoxetine will reduce syncope and improve quality of life.

The investigators will seek to determine the effects of different heart rates on both stroke volume and cardiac output using non-invasive hemodynamic assessments. In order to safely manipulate the HR, the investigators will study patients with permanent pacemakers in whom heart rate manipulation can be done in a safe and non-invasive manner.

Syncope is a common condition which can disturb daily functions of the patients and impair their quality of lives. It contributes to 0.8 to 2.4% of the visits of emergency rooms. Noticeably, studies demonstrated that the lifetime prevalence of syncope is as high as 41% with a 13.5% recurrence rate. The cornerstone of the treatment of vasovagal syncope (VVS), the most common type of syncope, is lifestyle modifications and patient education to avoid potential triggers of syncope. These recommendations alleviate vasovagal spells in many patients; however, some patients experience life-disturbing vasovagal attacks despite compliance with these modifications. This fact underscores the importance of efficient pharmacological interventions as well. Currently, there is an ongoing controversy about the efficacy of midodrine and fludrocortisone as adjunct pharmacological interventions for the prevention of VVS. In the COMFORTS trial, we are going to evaluate the efficacy of midodrine, fludrocortisone, and lifestyle modifications for prevention of vasovagal attacks in patients with VVS.

Multicenter Italian interventional "proof of efficacy" clinical trial that aims to evaluate the incidence of asystolic pauses and heart rate in patients with CNS who performed severe CNA identified through asystolic pauses identification by implantable loop recorder. The study is independent, "investigator-initiated," sponsored by a nonprofit scientific association called the Italian Multidisciplinary Group for the Study of Syncope (GIMSI).