View clinical trials related to Tachycardia, Ventricular.
Filter by:The supra ventricular tachycardia is the most common symptomatic arrhythmia in pediatrics. Amiodarone is an antiarrhythmic drug used in this indication. Pharmacokinetic, efficacy and safety data are not known in the pediatric population due to the lack of a suitable specialty available on the market. The development of an amiodarone oral solution formulation adapted to this age group should provide a therapeutic alternative and collect data on the pharmacokinetics, efficacy, acceptability and tolerability of the drug.
The purpose of this study is to determine how the position of the right ventricular (RV) coil of an implantable cardioverter defibrillator (apex versus septum) affects the defibrillation threshold; specifically, can defibrillator threshold be improved by implantation site selection.
The intent of this observational study is to understand the role of non-invasive programmed stimulation (NIPS) to induce substrate based MMVT (Monomorphic Ventricular Tachycardia) in patients receiving new St. Jude Medical Implantable Cardioverter Defibrillator (ICD) or Cardiac Resynchronization Therapy Defibrillation (CRT-D) systems.
The heart beat is controlled by electrical signals. Following a heart attack, part of the heart muscle dies and is later replaced by scar tissue. Within this area of scar, there often remain "channels" of surviving tissue still able to transmit electrical signals. However, it is well established that these "conduction channels" (CC) can form a short circuit around the scar, leading to electrical disturbances (arrhythmias) that are potentially life threatening. The commonest of these is ventricular tachycardia (VT), and is estimated to cause 300,000 deaths per year. One recognised treatment option of VT involves burning (ablation) these "conduction channels" (CC) within the scar. However, at present, the procedure is long and is far off 100% effective. Consequently, current best practice does not rely on treating the VT, but rather preventing it from causing sudden death - this is achieved with an Implantable Cardioverter Defibrillator (ICD), a device which can recognise when a patient is in VT and deliver an internal shock to restore the normal electrical conduction. Patients with defibrillators subsequently are subject to recurrent painful and debilitating shocks which, although lifesaving, significantly reduce their quality of life. The limitation with ablation at present is due to the difficulty in visualising these CC's. Investigators at Imperial College have created a novel electrogram visualisation program, Ripple Mapping (RM), which they have already found to be superior to currently used programmes in cases of arrhythmias in the upper chambers of the heart (the atria). During a retrospective study in patients with scar related VT following a heart attack, when ablation was delivered in areas associated with identified Ripple Mapping Conduction Channels, these patients remained free of VT recurrence for >2 year follow up interval. The study hypothesis is that Ripple Mapping can identify all conduction channels within scar tissue critical to the VT circuit, ablation of which will lead to long-term freedom from VT and ICD therapies. The investigators now aim to perform a prospective randomised study comparing Ripple Mapping guided VT ablation against conventional VT ablation.
The aim of this study is to screen a well characterized patient population with ventricular tachycardia of unknown origin and treated with an implantable cardioverter-defibrillator (ICD) for mutations in the calmodulin genes.
This study aims to compare antiarrhythmic drug therapy with catheter ablation using the SmartTOUCH catheter (Biosense Webster Inc.) as treatment for patients with ventricular tachycardia and coronary artery disease
Ventricular tachycardia (VT) is a morbid arrhythmia responsible for many sudden deaths and ICD shocks. Despite much progress in the treatment of arrhythmia, VT remains a therapeutic challenge. Most patients with VT have an implantable cardioverter defibrillator (ICD) for secondary prevention of sudden cardiac death, however, an ICD merely treats VT, it does not prevent VT. In patients with recurrent VT and ICD shocks, two strategies are available to decrease the burden of VT. The first is antiarrhythmic drugs, and the second is VT ablation. The aim of this study is to compare the efficacy of antiarrhythmic drugs and VT ablation guided by MRI. VT can sometimes be suppressed with antiarrhythmic medications, however, these are often ineffective, and carry a high burden of side effects. Many forms of VT can be cured by selective destruction of critical electrical pathways with catheter ablation. A major limitation in the ablation of VT, however, is the time required to localize scar tissue and important pathways for targeting of lesions. Magnetic resonance imaging can now obtain reliable images of scar location within the ventricles. Recent advances in electroanatomical mapping systems allow operators to import pre-acquired images into the mapping system. The aim of this study is to examine the feasibility of importing historic MRI scar maps of the ventricles into the electroanatomical system and using such images to guide catheter ablation, as compared to antiarrhythmic drug suppression of VT. We suspect that MRI guidance will be especially useful in patients with "unstable" VT, i.e. VT that causes an abrupt drop in blood pressure, and thus cannot be maintained in the electrophysiology (EP) lab for mapping and entertainment purposes. Patients referred for VT ablation have ICDs. Through previously completed animal work (Circulation 2004; 110(5): 475-82) and a human trial (2006 Sep 19;114(12):1277-84) we have demonstrated the safety of MRI in the setting of pacemakers and implantable defibrillators using appropriate precautions. Through careful device programming and using MRI sequences with limited energy exposure (specific absorption rate < 2 W/kg) we will study the pre procedural myocardial anatomy of patients enrolled into this study. The primary endpoint will be lack of VT documented by implantable defibrillator (when present) interrogation or Holter monitoring 6 months post ablation. The secondary endpoints will be comparison of inducible arrhythmia at the end of the procedure, procedure time, comparison of endocardial voltage mapping to scar on delayed enhancement MRI images, and complications in each study arm.
Cardiac arrest or sustained VT (ventricular tachycardia) in patients with heart disease is best treated with an ICD (implantable cardioverter defibrillator). However, the ICD alone is not appropriate therapy for patients with frequent VT episodes. In fact frequent shocks for VT may predict a poorer prognosis. Anti-arrhythmic drugs are co-administered with ICDs in up to 50% of patients to prevent VT episodes, but antiarrhythmic drugs may have harmful effects. Thus improved drugs to prevent VT without interfering with ICD function are needed. Recent data including our own suggest that clonidine may be a new therapy to prevent ICD shocks. It may act centrally on sympathetic outflow and peripherally and selectively on cardiac Purkinje, to suppress and control VT occurring in patients. Our purpose is to test the hypothesis that clonidine reduces frequent VT better than beta blocker in patients with ICDs. After informed consent patients will be randomized in a single blind fashion to either clonidine or metoprolol given three times per day. Other prescribed drugs may be adjusted to promote toleration of the study drug. ICD interrogations of episodes of VT will be the primary endpoint. Device based NIPS (non-invasive programmed stimulation) testing in a subset of these patients will allow mechanistic understanding of the clonidine effect. All of the procedural techniques are in place as performed clinically; preliminary data are given showing feasibility of the project.
This is a prospective study to evaluating the ability of the PD2i Cardiac Analyzer to predict the risk of serious heart rhythm abnormalities in high-risk patients that do not already have an Implantable Cardioverter Defibrillator.