
Cryoablation for Monomorphic Ventricular Tachycardia (CryoCure-VT)
Monomorphic Ventricular TachycardiaA prospective, single-arm, multi-center, pre-market, clinical study designed to provide safety and performance data regarding the use of the Adagio Medical VT Cryoablation System in the treatment of ventricular tachycardia.

Effectiveness of the EMPOWER™ Modular Pacing System and EMBLEM™ Subcutaneous ICD to Communicate...
TachycardiaVentricular2 moreThe MODULAR ATP Clinical Study is designed to demonstrate safety, performance, and effectiveness of the Modular Cardiac Rhythm Management (mCRM) Therapy System.

Preventive VT Substrate Ablation in Ischemic Heart Disease
Ventricular TachycardiaVentricular Arrythmia5 moreThe investigators hypothesize that preventive VT substrate ablation in patients with chronic ICM, previously selected based on imaging criteria (BZC mass) for their likely high arrhythmic risk, is safe and effective in preventing clinical VT events.

Treatment Study of AV Node Reentry Tachycardia
Supraventricular TachycardiaCompare the effectiveness and safety of two techniques for modification of slow AV nodal pathway conduction underlying AVNRT: 1) New Ablation Technique, low voltage and wave front collision mapping vs. 2) the Standard Ablation Technique, an anatomical/electrogram approach.

Randomized Assessment of TcMS for VT Storm
Ventricular TachycardiaThree-arm randomized clinical trial comparing two strategies of TcMS to sham stimulation in patients with VT storm. The hypothesis of the study is that TcMS will reduce the burden of VT in the 24 hours after randomization compared to sham stimulation and that TcMS with theta burst stimulation (TBS) will be more effective at reducing VT burden than low frequency TcMS.

Catheter Ablation Versus Anti-arrhythmic Drugs for Ventricular Tachycardia
Heart Disease Structural DisorderVentricular Tachycardia10 moreSudden cardiac death (SCD) due to recurrent ventricular tachycardia (VT) is an important clinical sequela in patients with structural heart disease. VT generally occurs as a result of electrical re-entry in the presence of arrhythmogenic substrate (scar). Scar tissue forms due to an ischemic cardiomyopathy (ICM) from prior coronary obstructive disease or a non-ischemic cardiomyopathy (NICM) from an inflammatory or genetic disease. AADs can reduce VT recurrence, but have significant limitations in treatment of VT. For example, amiodarone has high rates of side effects/toxicities and a finite effective usage before recurrence. ICDs prevent cardiac arrest and sudden death from VT, but do not stop VT occurring. Recurrent VT and ICD therapies decrease QOL, increase hospital visits, mortality, morbidity and risk of death. Improvement in techniques for mapping and ablation of VT have made CA an alternative. Currently, there is limited evidence to guide clinicians either toward AAD therapy or CA in patients with NICM. This data shows significant benefit of CA over medical therapy in terms of VT free survival, survival free of VT storm and VT burden. Observational studies suggest that CA is effective in eliminating VT in NICM patients who have failed AADs, resulting in reduction of VT burden and AAD use over long term follow up. Furthermore, there is limited data on the efficacy of CA in early ICM with VT, or advanced ICM with VT. RCT data is almost exclusively on patients with modest ICM with VT, and this is not representative of the real-world scenario of patients with structural heart disease presenting with VT. Therefore the primary objective is to determine in all patients with structural heart disease and spontaneous or inducible VT, if catheter ablation compared to standard medical therapy with anti-arrhythmic drugs results in a reduction of a composite endpoint of recurrent VT, VT storm and death at a median follow up of 18 months.

imPROving Quality of LIFe In the Long COVID Patient
Post-COVID-19 SyndromeLong COVID9 moreThe purpose of this study is to investigate the efficacy of orally administered nirmatrelvir/ritonavir compared with placebo/ritonavir to improve quality of life in non-hospitalized adult participants suffering from post-acute COVID-19 syndrome.

Auricular Vagal Nerve Stimulation for Hypermobile Ehlers-Danlos Syndrome
Functional Gastrointestinal DisordersHypermobile Ehlers-Danlos Syndrome3 moreHypermobile Ehlers-Danlos Syndrome (hEDS) is a connective tissue disorder characterized by hyperextensible skin, joint hypermobility and additional connective tissue manifestations. For unclear reasons, hEDS is associated with many gastrointestinal (GI) and autonomic nervous system (ANS) complaints such as postural orthostatic tachycardia syndrome (POTS). This study will address the clinical relationship between hEDS/Hypermobile Spectrum Disorders and autonomic regulation and see if there is a benefit of two forms of non-invasive vagal nerve stimulation therapies to reduce GI symptoms in hEDS and POTS. The study will also investigate plausible effects of these nerve stimulation therapies on gastric function and autonomic signaling.

Stereotactic Ablative Radiotherapy for the Treatment of Refractory Ventricular Tachycardia
Radiotherapy; ComplicationsVentricular Tachycardia2 moreVentricular 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.

Paediatric Syncope in the Emergency Department
SyncopeVasovagal2 moreThe 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.