View clinical trials related to Syncope, Vasovagal.
Filter by:The purpose of this study is to perform a prospective evaluation of the vasovagal syncope prediction algorithm, called Tilt Test Analyzer, during head up tilt testing tests in one center in the United Kingdom.
Syncope affects about 50% of Canadians, is the cause of 1-2% of emergency room visits, and probably is responsible for CDN $250 million in health care spending each year. It is associated with decreased quality of life, trauma, loss of employment, and limitations in daily activities. The most common cause is vasovagal syncope. This occurs in people of all ages, and is a lifelong predilection. While the median number of faints in the population is 2, those who come to the investigators care have a median 10-15 lifetime spells, and have an increased frequency in the year before presentation. Vasovagal syncope is due to abrupt hypotension and transient bradycardia, which cause cerebral hypoperfusion. The pathophysiology may be either failure of venous return or progressive vasodilation, both due to inappropriately low sympathetic outflow. Sympathetic stimulation might be involved early in the reflex cascade. There is no known medical treatment for frequent fainting. The investigators performed the pivotal CIHR-funded randomized trials that showed that neither permanent pacing, beta blockers, nor fludrocortisone help the majority of patients. However 3 observational studies suggested that beta blockers prevent syncope in older subjects, and the Prevention of Syncope Trial (POST1) showed in a prespecified, -stratified analysis that patients ≥42 years tended to benefit. The investigators recent meta-analysis showed a benefit from metoprolol in these patients, with a hazard ratio of 0.52 (CI 0.27 to 1.01), and an age-specific response to beta blockers (p = 0.007). These results suggest the need for a randomized clinical trial of metoprolol for the prevention of vasovagal syncope in older subjects. Accordingly,the investigators conducted a poll of 48 cardiologists and neurologists in Canada and abroad: 98% stated that a randomized trial was necessary, and 92% agreed to participate in such a trial. Separately, this study emerged as the first choice for syncope randomized trials after consultation with Canadian and international experts. Objective: To determine if treatment with metoprolol in patients ≥40 years old with moderate to severely frequent vasovagal syncope will better suppress syncope recurrences than placebo. Methods: This will be a longitudinal, prospective, parallel design, placebo-controlled, randomized clinical trial. Patients will be enrolled during a recruitment period of 4 years and followed for a fixed period of 1 year. Subjects will have had ≥1 faint in the previous year, and a diagnosis of vasovagal syncope based on a quantitative diagnostic score. They will be randomized to receive either metoprolol or placebo at an initial dose of 50 mg bid. Dose adjustments will be made according to treating physician discretion to optimize tolerance and compliance while maximizing dose. The primary outcome measure will be the time to the first recurrence of syncope (after a 2 week dose titration wash-in period) over the 1-year observation period. The primary analysis will be performed on an intention-to-treat basis. Secondary analyses will include an on-treatment analysis, as well as analyses comparing syncope and presyncope frequency, number needed to treat, quality of life, impact of syncope on daily living, and cost from the perspective of the publicly funded health care system. The investigators will enroll 248 patients to have an 85% power to detect a reduction (p<0.05) in the primary outcome from 50% (placebo group) to 30% (midodrine group), a 40% relative risk reduction. This sample size also allows for a 11% rate of subject dropout with loss to follow-up before a syncopal event. The University of Calgary Syncope Clinic has a well-functioning clinical trial apparatus that successfully completed the randomized, multicenter Prevention of Syncope Trials (POST1: metoprolol for vasovagal syncope; POST2: fludrocortisone for vasovagal syncope) and SIRCAT (Statin-Induced Reduction of Cardiomyopathy Trial). Enrolment is underway in the CIHR-funded POST3 (pacing versus loop recorders in syncope patients with bifascicular block) and POST4 (midodrine for vasovagal syncope). Study centres that were highly productive in POST1-4 have agreed to participate. The investigators therefore will have ample syncope enrolling centres. Relevance: This study will provide evidence to inform the use of metoprolol in the treatment of moderate to severely frequent syncope in older patients with vasovagal syncope. Given the lack of any other conventional medical therapy the investigators expect it to have rapid impact on care.
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.
The purpose of this study is to evaluate the effectiveness of cardioneuroablation for the treatment of neurocardiogenic syncope (NCS), also known as "vaso-vagal" syncope. Syncope is a general term for passing out spells and neurocardiogenic syncope is a specific form of passing out spells caused by sudden drops in heart rate or blood pressure. Although the specific mechanisms of NCS are not well understood, it is believed that some people are prone to developing passing out spells in specific situations such as standing up for a long period of time, pain or nausea. In these situations, the body reacts with a paradoxical reflex which leads to a drop in blood pressure and heart rate and causes passing out. Certain types of medications are used to treat NCS including beta-blockers, midodrine and florinef, among others. However, none of these medications are particularly effective at preventing passing out spells and many people continue to have episodes despite trying different medications. Cardioneuroablation is a new form of treatment for NCS. The term ablation means using a wire to make small electrical burns in the heart. Ablation has been used for many years to treat other electrical disturbances in the heart but the use of ablation to treat NCS is a new application. The goal of cardioneuroablation is to identify areas within the heart which are believed to initiate the reflex which triggers the drop in heart rate and blood pressure that leads to passing out. In preliminary studies, it has been suggested that cardioneuroablation may be significantly more effective than medications at preventing passing out spells for people with NCS. Hypothesis: Cardioneuroablation of vagal inputs in the left atrium may serve as an effective treatment modality for the prevention of NCS by blunting the initial trigger of the cascade that leads to symptoms and syncope.
Patients's demographics and perioperative factors affect the occurrence of hypotensive bradycardic events in the patients undergoing arthroscopic shoulder surgery in the sitting position under interscalene block.
Vasovagal Syncope (simple postural faint) is the most common cause of acute loss of consciousness. Postural tachycardia syndrome(POTS) is the most common chronic form of postural lightheadedness. Together they afflict many Americans, mostly young women, who are prevented from gainful employ or school attendance. The underlying mechanism is not known. Our past work suggests that a simple molecule, nitric oxide, acts to subvert normal blood flow controls causing blood to pool in the gut when standing. Our proposal will show the mechanism behind this problem and will indicate effective medical treatments. Patients will be compared to healthy control subjects.
Syncope is a common problem that many clinicians may encounter in various outpatient settings. Neurocardiogenic syncope (NCS) is a benign condition characterized by a self limited episode of systemic hypotension. Patients are usually managed with education on syncope, anxiety management, and coping skills. It has been established that practice of Yoga could relieve stress and anxiety. In a different study, they also found that Yoga positively influences cardiovascular function by decreasing the heart rate and blood pressure. The main objective of Yoga is to achieve control over the autonomic nervous system and able to control functions like heart rate, blood pressure and respiratory rate. Based on the findings that Yoga relieves stress and reduces heart rate, the investigators propose to study if Yoga can decrease the frequency of NCS and also reduce the symptoms associated with these episodes.
Physiological stimulation therapy effectiveness will be proved with contractility sensor or CLS sensor (Closed Loop Stimulation), in BIOTRONIK CLS pacemakers to prevent from neuromediated syncope. Furthermore, not only will be investigated if this system eradicates syncopes, but also if the number of presyncopal episodes is reduced.
Dysautonomia, primarily defined as postural orthostatic tachycardia syndrome (POTS) can seriously disrupt a child's daily activities. It is most commonly associated with nausea or abdominal pain. In preliminary studies, when orthostatic intolerance was treated with fludrocortisone, a standard therapy for orthostatic intolerance (OI), symptomatic improvement in nausea was observed. However, children with POTS were also observed to have higher supine mean arterial pressure (MAP) (preliminary data) and greater suppression of the baroreceptor reflex sensitivity (BRS) occurred upon up-right tilt. While fludrocortisone alleviates nausea associated with OI, its long-term use may pose long term health risks to children including worsening hypertension. Therefore, it is the objective of this study to define the mechanism for OI as it relates to nausea. The investigators hypothesize that OI resulting from changes in the autonomic nervous system is the likely mechanism for the nausea observed in the patients in this study. The investigators further hypothesize that this is potentially an early marker for future cardiovascular problems such as early onset hypertension and cardiac hypertrophy. The general objective of this protocol is to address this gap in knowledge by determining the autonomic characteristics of children with OI as well as defining neurohumoral profiles for these subjects to better understand the cause of the elevated supine in these subjects. By better understanding the potential mechanism for this condition, it is the investigators future goal to develop a more focused and safer treatment strategy. The investigators will study subjects between 10 to 18 years of age utilizing the tilt table to mimic daily life stressors and also measure serum levels of epinephrine, norepinephrine, rennin, angiotensin II, aldosterone, and vasopressin at baseline and during tilt. This study will generate data with high impact in that more rational treatments for management of dysautonomia could be chosen on the basis of the profile of dysautonomia and neurohumoral markers.
About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving and have reduced quality of life. There are no therapies that have withstood the test of adequately designed and conducted randomized clinical trials. Midodrine is a prodrug whose metabolite is an alpha-1 adrenergic agonist that increases venous return to the heart and raises blood pressure. There is considerable lower level evidence that it might prevent vasovagal syncope. The investigators will test the hypothesis that Midodrine prevents recurrences of syncope in patients with moderate to severe vasovagal syncope.