View clinical trials related to Syncope.
Filter by: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.
At least 5% of patients with vasovagal syncope also have Sleep Syncope. Patients awake from sleep with profound malaise and gastrointestinal vagal symptoms. About 75% have severe nausea and about 40% have lower abdominal cramps. Some faint while supine, but most find their symptoms so severe that they rise quickly and hurry to the bathroom. Sometime either on the way to the toilet, near it, or shortly afterwards they faint. The nausea is followed by vomiting, and the cramps by watery diarrhea. After relief the patients remain presyncopal, diaphoretic, and tired. Almost all patients also have clinical vasovagal syncope during daytime hours. The cause of this is unknown. Orthostatic stress cannot be a factor in triggering the event, and in isolated case reports it occurs during non-REM sleep. There is no classic provocative situation of pain, the sight of trauma, or the presence of medical settings. These suggest the importance of central processes and the reduced likelihood that strategies that target maintaining preload (such as with midodrine and fludrocortisone) would be helpful. As well, midodrine is avoided during the night. Recently the investigators reasoned that if the investigators could rapidly suppress the nausea patients could remain supine, wait out the nausea, and not faint with orthostatic stress. Ondansetron is a potent anti-nausea medication that has rapidly dissolving preparations. Nine patients were instructed to keep one at the bedside, insert it upon waking up with nausea, remain in bed, and raise their legs (if possible). There was partial success with ondansetron 4 mg and complete success with ondansetron 8 mg. This remarkable but anecdotal observation requires formal testing. Research Objectives: the investigators will test the hypothesis that ondansetron 8 mg prn sublingually on awakening with moderate to severe nausea prevents loss of consciousness in patients with prior Sleep Syncope who awaken with malaise and nausea. Study Design & Methodology: The main study will be a placebo-controlled, double-blind, randomized, crossover clinical trial. The primary outcome will be the progression of awakening with nausea to syncope. Thirty patients with Sleep Syncope will be randomized 1:1 to receive packages of either ondansetron 8 mg sublingual tablets or matching placebo. They will each receive 3 boxes of 10 tabs, with refills available if needed. Each crossover period will last 6 months. In a substudy the investigators will test whether the predominant disturbed physiology is bradycardia, decreased venous return, or decreased systemic vascular resistance. This will be assessed using a unique, small, wearable blood pressure sensor that can be rapidly donned on the ear. It records heart rate and beat-to-beat waveforms, which permit estimating stroke volume, systemic vascular resistance, and cardiac output. the investigators will record these variables in all patients continuously from when the device is put on until 30 minutes afterwards. the investigators hypothesize that unlike during syncope provoked by head-up tilt testing, here there will be no decrease in preload until patients arise, and that the main physiologic disturbance during syncope is hypotension due to decreased preload superimposed on heart rate collapse. Anticipated Outcomes: If successful, this research would be i) the first to report a well-tolerated and highly effective treatment for most sleep syncope, and ii) the first to report the physiology of brain-initiated vasovagal syncope in the community outside a laboratory environment.
The study will systematically evaluate how an emergency manual-a collection of checklists and fact sheets-affects the performance of resuscitation teams during the management of priority one patients in an emergency department.
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.
The incidence and severity of hot weather and extreme heat events (heat waves) is increasing. As such, there is an urgent need to develop heat-alleviation strategies that can provide targeted protection for older adults who are at an elevated risk for heat-induced illnesses or death due to impaired body temperature and cardiovascular regulation. While air-conditioning provides the most effective protection from extreme heat, it is inaccessible for many individuals and cannot be used during power outages (e.g., heat-related rolling blackouts). Immersion of the lower limbs in cold water and/or the application of cold towels to the neck have been recommended as simple and sustainable alternatives to air-conditioning. However, empirical data to support the efficacy of these interventions for mitigating physiological strain and discomfort in older adults is lacking. To address this knowledge gap, this randomized crossover trial will evaluate the effect of lower limb immersion with and without application of cold towels to the neck on body core temperature, cardiovascular strain and autonomic function, dehydration, and thermal comfort in adults aged 65-85 years exposed to simulated heat wave conditions (38°C, 35% relative humidity) for 6 hours.
The goal of this observational study is to examine the clinical presentations, the diagnostic tests performed and the management of patients presenting with transient loss of consciousness (TLOC) The main questions it aims to answer are: - prevalence of TLOC - prevalence of different diagnoses leading to TLOC Demographic, clinical, paraclinical and biological data will be collected from the emergency medical file
This study is a prospective, single-center randomized controlled clinical trial. patients with refractory vasovagal syncope were randomly divided into two groups according to the proportion of 1:1. Group A: simple left atrial ganglion plexus ablation (RAGP + LSGP + LLGP + LIGP + RIGP ablation); B group: left atrial ganglion plexus combined with right atrial ganglion plexus ablation (group A + consolidation ablation of RAGP at the junction of right atrial septum and superior vena cava). To clarify the role of RAGP in cardiac autonomic nervous system and the effect of ablation, to establish the standard stragtegy of cardiac nerve ablation.
Background: Autonomic system modification is an established therapeutic approach that has been increasingly used for the treatment of vagal-related symptomatic bradycardia, such as cardio-inhibitory vasovagal syncope1-12. Although convincing results had been reported from small populations, a large randomized study providing robust evidence on the efficacy of this approach has not yet been performed. Hypothesis: Cardiac autonomic system modification is effective for the treatment of vagal-related symptomatic bradycardia, and is associated better clinical results as compared to placebo.
Prospective multi centre cohort study examining the clinical presentation, diagnostic tests, and management of adult Emergency Department (ED) patients presenting with Transient Loss of Consciousness (TLOC) either undifferentiated or thought to be of syncopal origin.