Efficacy of a Right-sided Ablation of the Anterior Ganglionated Plexus for Neurally Mediated Syncope...
SyncopeNeurogenic1 moreThe third study on CardNM (CardNMH3 study) is a multicenter, double-blind, randomized trial with a sham control group investigating the efficacy and safety of a computed tomography (CT)-guided, right-sided ablation of the anterior ganglionated plexus to prevent recurrence of syncope in patients with neurally mediated syncope (NMS). The primary goal of the study is to determine whether a CT-guided, right-sided ablation of the anterior ganglionated plexus safely reduces the risk of recurrent episodes of syncope in patients with a history of recurrent NMS. Two-third of the patients will be randomized to the active arm and one-third to the control arm (sham). The study procedure is described in the 'detailed description' and 'intervention description'. Syncope burden, syncope occurrence and quality of life will be assessed by questionnaires at baseline and at 1, 3, 6 and 12 months. A 24-h rhythm registration will be performed at baseline and at 1-, 3- and 6-month follow-up to investigate the influence of the intervention on heart rate. The effect of CardNM on blood pressure and on chronotropic sinus node function will be evaluated in 2 additional substudies. Patients enrolled in the blood-pressure substudy will undergo a 24-h blood pressure monitoring at baseline and at 1, 3 and 6 months. Participants in the sinus node competence substudy will undergo a bicycle exercise test at baseline and at 1, 3 and 6 months. Investigators aim to achieve complete follow-up for 110 patients who meet the study enrollment criteria. If syncope-free survival (primary endpoint) is significantly different between the 2 arms after the enrollment of fewer than 110 patients (minimum 55 patients), enrollment into the trial will be prematurely stopped. The study may also be terminated prematurely if safety concerns occur.
Assessment of Stroke Volume and Cardiac Output in Response to Varying Heart Rates
Vasovagal SyncopeThe 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.
Midodrine and Fludrocortisone for Vasovagal Syncope
SyncopeVasovagalSyncope is a common condition which can disturb daily functions of the patients and impair their quality of lives. It contributes to 0.8 to 2.4% of the visits of emergency rooms. Noticeably, studies demonstrated that the lifetime prevalence of syncope is as high as 41% with a 13.5% recurrence rate. The cornerstone of the treatment of vasovagal syncope (VVS), the most common type of syncope, is lifestyle modifications and patient education to avoid potential triggers of syncope. These recommendations alleviate vasovagal spells in many patients; however, some patients experience life-disturbing vasovagal attacks despite compliance with these modifications. This fact underscores the importance of efficient pharmacological interventions as well. Currently, there is an ongoing controversy about the efficacy of midodrine and fludrocortisone as adjunct pharmacological interventions for the prevention of VVS. In the COMFORTS trial, we are going to evaluate the efficacy of midodrine, fludrocortisone, and lifestyle modifications for prevention of vasovagal attacks in patients with VVS.
Italian Cardioneuroablation Study for Neurocardiogenic Syncope Patients
Neurally Mediated SyncopeMulticenter 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 Effect of Water Carbonation on Orthostatic Tolerance
Orthostatic HypotensionSyncope1 moreThe 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.
ConfirmRxTM: Posture and Activity
SyncopeCryptogenic StrokeInsertable Cardiac Monitor's (ICM's) such as Confirm Rx™ are leadless devices implanted for long-term heart rhythm monitoring in the diagnosis and management of clinical conditions such as recurrent unexplained syncope, cryptogenic stroke, ventricular arrhythmias and monitoring atrial fibrillations (AF) post ablation. There is limited data on variations seen in signal sensing with changes in physical activity and posture. This single arm, non-randomized, open-label, multi-center, clinical investigation of 100 subjects is designed to characterise the safety and performance of Confirm RxTM by assessing quality of signal attained from the device with changes in posture and physical activity at implant and 30days post procedure. The study is also intended to assess gross migrations of the device at 30days post implant.
Different Catheter Ablation Strategy in Vasovagal Syncope
SyncopeVasovagalThis 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.
REmote Cardiac MOnitoring of At-risk SYNCope Patients After Emergency Department Discharge -RCT...
SyncopeSyncope (fainting) is a common reason for emergency department (ED) presentation. Fainting can be caused by heart conditions such as irregular heart rhythm (arrhythmia) that can be life-threatening, structural heart problems, or serious conditions not related to the heart. The standard or usual treatment for the majority of patients at-risk for irregular heart rhythm is getting discharged home with no heart rhythm monitoring. If patients receive any monitoring, only Holter monitoring device that records all heart beats for 24 hours to 72 hours will be used. One-third to half of irregular heart rhythm will be identified only after patients are either discharged from the ED or hospitalized in an inpatient unit. One-third to half of irregular heart rhythm will be identified only after patients are either discharged from the ED or hospitalized in an inpatient unit. The study hypothesize that prolonged live cardiac rhythm monitoring (15 days) of at-risk syncope patients, discharged from the ED, will lead to identification of irregular heart rhythm, which can lead to improved patient safety and lower healthcare costs.
Assessment of Metoprolol in the Prevention of Vasovagal Syncope in Aging Subjects
Vasovagal SyncopeSyncope 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.
Lower Body Muscle Pre-activation in Initial Orthostatic Hypotension
Orthostatic IntoleranceSyncope2 moreThis study is aimed primarily at providing a simple and effective form of treatment to reduce the symptoms of Initial Orthostatic Hypotension (IOH) and prevent syncope. We will first characterize the physiology of IOH, and then we will study four sit-to-stand maneuvers, each with a different stress tests to identify the role of sympathetic activity vs. simple muscle contraction in IOH. Then we will complete an additional two sit-to-stands with interventions designed to decrease the blood pressure drop (and hopefully symptoms) with initial stand. These consist of physical counter maneuvers, which may be a possible treatment that can be used to mitigate the drop in blood pressure (BP) seen in IOH during a stand and relieve presyncope symptoms.