Active clinical trials for "Tachycardia"

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.

Ventricular tachycardia (VT) is an abnormal rhythm arising from the bottom chambers (ventricles) of the heart. The hearts of most patients who develop VT have been previously damaged by a myocardial infarction (heart attack) or other heart muscle diseases (cardiomyopathies). The damage produces scar or fatty deposits that conduct electrical impulses slowly allowing VT to occur. Recurrent episodes of VT can compromise heart function and increase mortality. VT is prevented by special drugs but these are not always effective and can have many side effects. Most patients with VT will also have a specialised device called an implantable defibrillator (ICD) implanted. The ICD treats VT by either stimulating the heart rapidly or delivering a shock to it. ICDs are very effective but the shocks are painful and have a big impact on quality of life. If VT occurs despite optimal drug treatment, patients undergo an invasive procedure called catheter ablation. Here, wires are passed into the heart from the blood vessels in the leg and the damaged heart muscle causing the VT is identified whilst the heart is in VT. An electrical current is passed down the wire making its tip heat up allowing discrete burns (ablation) to be placed inside the heart. The ablated heart muscle doesn't conduct electricity which stops the VT and prevents it recurring. Some patients are so frail that ablation cannot be performed safely. A recent clinical trial has shown that VT can be treated in such patients using radiotherapy, which is usually used to treat tumours with high energy radiation. This approach is non-invasive, painless and requires no sedation or anaesthesia. This study will test whether VT can be successfully treated using stereotactic ablative radiotherapy. This can deliver high dose radiotherapy very precisely, whilst minimising the risk of damage to healthy tissues.

The investigators will assess the efficacy of clinically recommended counterpressure maneuvers (CPM) in preventing syncope for paediatric patients. Participants presenting to the emergency department (ED) will first provide written informed consent. In stage I, they will be asked to complete a brief survey documenting the presentation of their syncopal episode, and any prodromal symptoms they experienced. Participants that consent to the second stage of the study will either receive usual care (control arm) or training in counter pressure maneuvers alongside usual care (intervention arm; leg crossing, bending, arm tensing). These patients will be followed for one years time, and will be asked to complete monthly surveys detailing their syncopal and presyncopal recurrence. Medical records will be accessed over the duration of the study to identify any changes in medical diagnosis.

Objective: To explore in our center the feasibility and safety of a SBRT treatment method for VT. Study population: Patients with ventricular tachycardia that are refractory to dose-escalated antiarrhythmic drugs and where catheter ablation has either already been performed or is deemed to be unsuccessful or associated with high risks. Intervention: Patients will be treated with a stereotactic body radiotherapy technique as a single fraction treatment up to a dose of 25 Gy delivered to the VT substrate defined by electrophysiological mapping. Main study endpoints: The primary aim is to explore the feasibility and safety of a SBRT treatment method for refractory VT. Secondary endpoints include an assessment of the efficacy of the treatment, quality of life, late toxicity and overall survival. Patients will have to fill in a quality-of-life questionnaire before and after the radiotherapy treatment. The risk associated with this trial is an increase in toxicity.

The purpose of this study is to assess the performance and safety of using the investigational catheter.

Ventricular tachycardia (VT) is a malignant cardiac arrhythmia subjecting our patients to a high risk of sudden death, increased morbidity and reduced quality of life. Unfortunately, failure of treatment is common and VT recurrences remain an important concern. In these patients, stereotactic arrhythmia radiotherapy appears to be an effective and safe treatment. The mechanism of action however remains unknown and should be elucidated. The objective of this phase 2, single arm, monocenter, pre-post intervention study is to evaluate the efficacy and safety of stereotactic arrhythmia radiotherapy and obtain insights in the mechanism of action by evaluating electro-anatomical alterations of stereotactic arrhythmia radiotherapy in patients with therapy refractory ventricular tachycardia.

Cardiac arrhythmia, specifically paroxysmal supraventricular tachycardia (SVT), accounts for a substantial proportion of emergency medical services resources utilization. Restoring a normal sinus rhythm (reconversion) should be done quickly and effectively. Reconversion requires increasing the atrioventricular node's refractoriness, which can be achieved by vagal maneuvers, pharmacological agents, or electrical cardioversion. The Valsalva Maneuver (VM) is a commonly used non-invasive reconversion method. It increases myocardial refractoriness by increasing intrathoracic pressure for a brief period, thus stimulating baroreceptor activity in the aortic arch and carotid bodies, resulting in increased parasympathetic (vagus nerve) tone. The effectiveness of conventional vagal maneuvers in terminating SVT, when correctly performed, shows a considerable variation ranging from 19.4% to 54.3%. To improve the effectiveness of the Valsalva Maneuver, the Modified Valsalva Maneuver (MVM) was introduced. While the standard VM is performed when the patient is in a sitting position (45°-90°), the modified VM involves having the patient sit up straight and perform a forced expiration for about 15 seconds, after which the patient is brought into a supine position with the legs raised (45°) for another 15 seconds. This modification should increase relaxation, phase venous return, and vagal stimulation. A recent meta-analysis demonstrated a significantly higher success rate for reconversion to sinus rhythm when using the MVM compared to the standard VM in patients with an SVT (Odds Ratio = 4.36; 95 percent c.i. 3.30 to 5.76; P < .001). More adverse events were reported in the MVM group, although this difference is not significant (Risk Ratio = 1.48; 95 percent c.i. 0.91 to 2.42; P = .11). The available evidence suggests that medication use was lower in the MVM group than in the standard VM group. However, medication use could not be generalized across the different studies. None of the included studies in this review showed a significant difference in length of stay in the emergency department (ED). Hence, the gain of implementing MVM is a higher rate of success with non-invasive reconversion methods. While the available evidence is highly suggestive of supporting the use of the MVM compared to the standard VM in the treatment of adult patients with SVT, implementation seems difficult. Current evaluations, such as the 'gold-standard' randomised controlled trial (RCT) design, rarely adequately or even explicitly address the context-specific drivers behind implementation outcomes and their relationship to the underlying programme theory, making it difficult to interpret their findings in light of other programmes in different settings. As a result, few evaluation strategies are widely accepted as appropriate. The net benefit of interventions and understanding how variable outcomes are achieved remains empirically uncertain. Therefore, it is essential to develop comprehensive, rigorous, and practical methods to evaluate people-centred quality improvement programmes, inform the selection of effective and efficient interventions, and facilitate improvement and scaling-up. In evaluating such complex interventions, the Medical Research Council (MRC) argues for the importance of process evaluation in conjunction with outcome evaluation to account for variability in implementation. The MRC's process evaluation framework guides evaluators to understand the implementation processes (what is implemented and how), mechanisms of intervention (how the delivery of the intervention produces change) and contextual factors that affect implementation and outcomes. Research question This study aimed to evaluate a quality improvement program to improve the non-invasive care for patients with paroxysmal supraventricular tachycardia in the emergency department.

About 30% of ischemic strokes are cryptogenic. Patent Foramen Ovale (PFO) is present in about 25% of the general population. In cryptogenic strokes, PFO has been shown to be overrepresented and recent intervention studies have confirmed that PFO has a causal link with stroke. In patients with recent cryptogenic stroke, these randomized studies have shown at least 50%-reduction of recurrent neurological events after PFO percutaneous closure compared with medical therapy alone. At the The risk of AF reported in these studies in certainly largely underestimated as only symptomatic and recorded episodes of AF have been declared. Patients often report palpitations without a dia gnosis of AF made on the ECG or a Holter. Long term ECG monitoring provides more accurate data on AF incidence. Administration of flecainide has been shown to be effective in preventing Atrial arrhythmia and may be useful in preventing these Atrial arrhythmia(AA) episodes after PFO closure. To the knowledge of the investigators, there is no study assessing the efficacy of any antiarrhythmic drug in the prevention of AFafter PFO closure. AFLOAT will be the first randomized study to possibly validate flecainide to prevent Atrial arrhythmia in these patients.

This study compares two arms - the current standard of care catheter ablation for Ventricular Tachycardia compared to stereotactic radiotherapy to non-invasively ablate ventricular tachycardia using a novel non-invasive ECG based body surface mapping technology. This allows investigators to identify ventricular tachycardia circuits to target for subsequent radio ablation. To summarize, the current standard of care invasive catheter ablation to the non-invasive radio ablation.

Compression Garments are a commonly prescribed treatment in Postural Orthostatic Tachycardia Syndrome (POTS). The effectiveness of a proof-of-concept compression garment has been demonstrated in an acute laboratory setting. It is not known if commercially available compression garments that participants wear in their every day lives are effective at improving heart rate and reducing symptoms in POTS. This trial will evaluate the use of commercially available waist-high and abdominal compression garments in adults diagnosed with POTS in a community setting.