View clinical trials related to Syncope, Vasovagal.
Filter by: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.
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.
The primary purpose of this investigation is to determine whether water carbonation can improve orthostatic tolerance in healthy control volunteers. Orthostatic tolerance refers to the ability to maintain an adequate blood pressure when standing. In some individuals blood pressure can fall when standing, predisposing to dizzy spells or fainting episodes. Drinking water can boost blood pressure and making fainting episodes less likely. However, it is not clear whether the carbonation of the water has any further impact on the blood pressure response. This is important because it may be that carbonated water expands the stomach (gastric distension), provoking an increase in sympathetic activity. The increase in sympathetic nervous system activity boosts blood pressure. Resolving this question would have important implications for patients with syncope. This study will test whether carbonated water will have any further impact on blood pressure than the already known effect of non-carbonated water.