View clinical trials related to Syncope, Vasovagal.
Filter by:Cardioneuroablation (CNA) is a promising tool to treat patients with asystolic reflex syncope. CNA acts through complete or near complete abolition of vagal nerve chronotropic and dromotropic effects on the heart, resulting in sinus node acceleration and improved atrio-ventricular conduction, which in turn prevents vagally-mediated reflex asystole. However, lack of parasympathetic protection may potentially be proarrhythmic, especially on the ventricular level. Whether this is a real threat is not known. Therefore, the aim of our study is to assess acute effects of CNA-induced total vagal denervation, measured by extracardiac vagal stimulation, on ECG and electrophysiological parameters as well as vulnerability to ventricular arrhythmias. The study group will consist of 50 consecutive patients undergoing CNA in our institution. Cardioneuroablation will be performed in standard manner. The following parameters will be assessed at baseline and after CNA (directly after CNA, after atropine injected after CNA and after isoproterenol bolus injected at the very end of the procedure): QTc interval, QT dispersion, right ventricular action potential duration, right ventricular effective refractory period and susceptibility to complex ventricular arrhythmias using programmed ventricular stimulation.
Cardioneuroablation (CNA) is a new promising method to treat reflex syncope which is due to vagally-induced functional sinus arrest or atrio-ventricular block (AVB). Although the procedure is effective in > 80% of patients, there are potential adverse effects associated with the lack of vagal protection. One of them is increased sinus rate and possible worsening of exercise capacity. However, it is not known how often this happens. Moreover, the most accurate tool to asses exercise capacity - cardiopulmonary exercise testing (CPET), has not yet been used in this group of patients. Therefore, the aim of the study is to assess one-year effects of CNA-induced total vagal denervation on cardiorespiratory fitness in patients undergoing CNA due to reflex asystolic syncope. The study group consists of patients undergoing CNA in our institution. All patients give informed written consent to undergo CNA and to participate in the study (Ethics Committee approval # 22/2024). CNA is performed according to standard protocol used in our institution. A symptom-limited cardiopulmonary exercise (CPET) is performed twice, at baseline (1-2 days before CNA) and after one year of follow-up. Standard CPET parameters are measured. Quality of life is measured using a dedicated questionnaire. Also, a control group of healthy volunteers will undergo CPET to answer the question whether subjects with reflex syncope differ in exercise capacity from healthy people.
Syncope is a common presenting condition. Pacemaker implantation can significantly reduce syncope recurrences in reflex syncope. However, despite careful selection, a substantial proportion of patients treated with pacemakers suffer recurrences of syncope. It is thought that a pronounced vasodepressor component may hinder the efficacy of pacing in patients, preventing adequate cerebral perfusion during the reflex, thus relativizing the anti-bradycardia function of the pacemaker to prevent syncope. It is hypothesised that the time elapsed from the actual loss of consciousness to the asystole recorded on the ECG during Tilt Table Test may be predictive in terms of response to pacemaker therapy, so this parameter becomes the subject of the present study.
The primary purpose of this study is to characterize cardiovascular autonomic function to emotional stimuli (blood-injection-injury phobia [needle phobia]) during an orthostatic (upright) challenge in individuals with and without known needle phobia. It is well established that emotional stress can produce hypotensive (low blood pressure) reactions. Interestingly, these hypotensive reactions to venipuncture (even with minimal blood drawn), insulin injections, finger sticks for blood sugar monitoring, dental care, and vaccinations can affect up to a quarter of adults and appear to be uniquely associated with blood-injection-injury phobia rather than other phobias. These hypotensive reactions can ultimately lead to a vasovagal syncope (fainting) response, and lead to increased avoidance of medical and dental procedures as a result of this phobia. Ultimately, this has severe implications on public health and places additional strain on the Canadian healthcare system. Currently, there is limited understanding surrounding the initiation of this response. Additionally, a comprehensive profile of cardiovascular autonomic function during exposure to provoking stimuli during orthostatic stress has not been captured in the literature. We will test individuals with and without blood-injection-injury phobia using our standard approach while exposing them to emotional stimuli.
The goal of this prospective cohort study is to study patients referred for sleep study by in-lab polysomnography in the Jordan University Hospital and the Jordan Hospital. The main aims are: - To prospectively obtain demographic and clinical information of patients referred for a sleep study. - To determine the diagnostic value of facial discoloration as potential marker for obstructive sleep apnea to increase detection rate for the condition. - To establish a correlation between obstructive sleep apnea and vasovagal symptoms with resulting increased smoking tendency and study the effect of treatment on the disorders. - To determine the association between timing of appearance of obstructive sleep apnea symptoms and initiation of smoking.
Reflex syncope is the most common form of syncope. It can lead to injuries and affect quality of life. Nonpharmacological and medical therapies have limited effectiveness. In certain patients, cardiac pacing seem to be beneficial. More recently cardioneuroablation (CNA) has emerged as a novel therapy for reflex syncope. The investigators aim to determine whether CNA is more effective than cardiac pacing at reducing the rate of cardioinhibitory-type reflex syncope.
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.
About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving, can be injured, and have poor quality of life. There are few therapies that have withstood the test of randomized clinical trials. the investigators will conduct a prospective, randomized, parallel, double-blind, proof-of-concept study that tests the hypothesis that serotonin 5HT3 receptor inhibition with ondansetron prevents tilt-induced vasovagal syncope (VVS) and pre-syncope in patients with clinical VVS. A total of 70 patients with quantitative clinical diagnostic criteria for VVS and at least 1 syncopal spell in the preceding year will be randomized in a double-blind acute phase 2 study to ondansetron 8 mg PO BID x 2 doses or matching placebo. The endpoint will be presyncope or syncope associated with diagnostic hemodynamic changes. These data should provide useful preliminary data as a foundation on which to conduct a subsequent randomized clinical trial.
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).
The present study aims to: 1. Estimate the prevalence of Postural Tachycardia Syndrome and vasovagal syncope among adults patients attend the Internal Medicine Clinic and ICU in period from 11/2022 to 10/2023 2. Detect of causes and the relationship between POTS and vasovagal syncope and serum electrolytes, and serum cortisol.