View clinical trials related to Vasovagal Syncope.
Filter by: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.
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.
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.
The essential arterial hypotension and allostasis registry is a prospective, observational research that has the purpose of demonstrating that essential blood pressure (BP) disorders and the associated comorbidities are a result of the inappropriate allostatic response to daily life stress. This required a functioning brain orchestrating the evaluation of the threat and choosing the response, this is a mind-mediated phenomenon. If the response is excessive it contributes to high BP, if deficient to low BP, and the BP itself will identify the allostatic pattern, which in turn will play an important role in the development of the comorbidities. To do so, consecutive patients of any age and gender that visit a cardiologist's office in Medellin, Colombia, are recruited. Individuals are classified according to their arterial BP and allostasis and follow them in time to see what kind of diseases develops the most (including BP) in the follow up according to the categorization of the characteristic chosen and after adjustment for confounder's variables. In addition, stress events with their date are registered. HYPOTHESIS The causes of the diseases are multifactorial. Physical, biochemical, psychological, social, and cultural dimensions of development dynamically interact to shape the health development process. A person´s health depends on their: 1. Biological and physiologic systems 2. External and internal environment (a) physical, b) internal behavioural and arousal state as registered by the brain. 3. Their interaction. The allostatic mechanisms to the internal and external stressors (allostatic load) involves a network composed by: 1. Functional systems; mediated by: 1. The Autonomic Nervous System 2. The endocrine system 3. The immune system 2. Structural changes: whenever the internal and/or external stressors are long lasting and/or strength enough, they may induce changes in: 1. Epigenetic, endophenotypes, polyphenism. 2. Plasticity 3. The interaction between a) and b). The network response do not affect exclusively the BP, propitiating the development of comorbidities, which may prompt strategies for prevention, recognition and ultimately, treatment. The allostatic model defines health as a state of responsiveness. The concept of psycho-biotype: The allostasis is the result of both: biological (allostasis) and psychological (psychostasis) abilities. It is proposed that both components behave in similar direction and magnitude. Immune disorders may be associated with the development of cancer. High BP population has a higher sympathetic and lower vagal tone, this has been associated with a decrease in the immune´s system function. Resources and energy depletion: Terms like weathering have been used to describe how exposures to different allostatic loads gradually scrape away at the protective coating that keeps people healthy. It is postulated that High BP individuals have more resources and energy.