View clinical trials related to Ventricular Tachycardia.
Filter by:A program of research has been set up at St. George's Hospital, London studyng the practicalities of catheter ablation. The current practice of catheter ablation is being studied for a range of arrhythmias including PAF, persistent AF, advanced persistent AF and resistant WPW.
Ventricular tachycardia (VT) contributes to over 350,000 sudden deaths each year in the US. Malignant VTs involve an electrical "short circuit" in the heart, formed by narrow channels of surviving tissue inside myocardial scar. An important treatment is to use catheter ablation to "block" the channel that forms the circuit. Effective ablation requires imaging guidance to visualize the VT circuit relative to scar structures in 3D. Unfortunately, with conventional catheter mapping, up to 90% of the VT circuits are too short-lived to be mapped. For the 10% "mappable" VTs, their data are only available during ablation and limited to one ventricular surface. This inadequacy of functional VT data largely limits the knowledge about scar-related VT and ablation strategies, and reduces the ability of clinicians to identify ablation targets and assess ablation outcome. The central hypothesis of this proposal is that functional VT data, integrated with CT or MRI scar data in 3D, can improve VT ablation efficacy with pre-procedural identification of ablation targets and post-procedural mechanistic elucidation of ablation failure. This research builds on the rapidly increasing clinical interest in electrocardiographic imaging (ECGi), an emerging technique that obtains cardiac electrical activity through inverse reconstructions from ECGs. The specific objective is to push the boundary of ECGi to provide - as a conjunction to intra-procedural catheter mapping - pre-ablation and post-ablation imaging of functional VT circuits integrated with 3D scar structure.
Background: Patients at increased risk for sudden cardiac death (SCD) may receive an implantable cardioverter defibrillator (ICD). The primary criterion for a primary prevention ICD implantation is a left ventricular ejection fraction (LVEF) below 35%, but refinement of ICD criteria is important since only a small proportion of ICD patients receives appropriate device therapy (ATP or a shock) during follow-up. Post-extrasystolic potentiation (PESP) may be a new risk marker for SCD. PESP is defined as a temporary increase in contractility that follows an extrasystolic beat (ESB) and is associated with myocardial calcium handling. In heart failure, changes in calcium homeostasis may lead to afterdepolarisations and thus predispose for SCD. PESP can be measured indirectly and non-invasively as post-extrasystolic blood pressure potentiation (PESP-BP). Abnormal PESP-BP was previously found to be an independent predictor of increased mortality in post-myocardial infarction patients with a reduced LVEF. However, it is unknown if this increased mortality in heart failure patients with abnormal PESP-BP is caused by an increased risk of SCD. Hypothesis: The investigators hypothesize that PESP-BP might be a new predictor of the occurrence of SCD, and can be used to enhance patient selection for primary prevention ICD therapy. Design: During scheduled device replacement ESB with various extrasystolic and post-extrasystolic coupling intervals will be evoked by electrical stimulation via the right atrial and ventricular device leads of the patient. Throughout the stimulation study blood pressure will be measured non-invasively a continuous electrocardiogram will be recorded. Either before or after the procedure, patients will undergo a 30-minutes assessment of spontaneous ESB, again with blood pressure and ECG recordings. Study population: 30 patients who are scheduled for device replacement or reposition, are eligible for this study; (1) 10 ICD patients who previously received appropriate device therapy (ADT); (2) 10 ICD patients who are free from ADT and (3) 10 dual-chamber pacemaker patients (control group). Outcomes: (1) Evoked PESP-BP (i.e. blood pressure differences between baseline, ESB and post-ESB); (2) Spontaneous PESP-BP (i.e. blood pressure differences between baseline, ESB and post-ESB); (3) Timing parameters (in ms): the basic cycle length interval; Extra-systolic interval (ESI); Post-extrasystolic interval (PESI).
Aim of this study is to collect data from pace mapping performed in three groups of patients : patients presenting ventricular tachycardia and infarction history, patients presenting infarction history without presenting ventricular tachycardia, and in patients without structural heart disease.
The goal of this study is to test the efficacy of the new imaging/simulation ("virtual heart") approach for determining the optimal ablation sites in patients with VT, which render post-infarction VT non-inducible. The study will test both the acute outcome of the ablation procedure, and the effect the use of the predicted targets has upon procedure time.
Sudden cardiac death is a frequent cause of cardiovascular mortality. Numerous rhythmic risk assessment criterion have been described targeting the substratum, the cardiac nervous tone or the trigger of arrhythmias. Development of ventricular tachycardia ablation in the past few years show interesting results preventing the recurrence of ventricular arrhythmias.
The implantable device therapy for cardiac arrhythmias has been an established therapy, and one of the common standard procedures in cardiac clinical practice. Pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy have been developed since 1960s, and the technologies in this field are still progressively developing. Not only these "traditional" implantable devices, there are multiple new devices for cardiac diseases, such as implantable loop recorder, vagal nerve stimulator and barostimulator. The aim of this registry is to demonstrate the efficacy and the safety of standard device implantation procedures and to evaluate/ identify specific factors, including clinical characteristics, laboratory data and procedural data, which predict the prognosis/complication of the patients. These identification will result in further improvement of patients' care.
Ventricular Tachycardia ablation in ischemic cardiomyopathy patients is required procedure in cases when anti-arrhythmic drugs failed. The concern is if adjunctive continuation amiodarone after ablation is needed.
Despite established implantable cardioverter-defibrillator (ICD) therapy and catheter ablation for sustained ventricular tachycardia (VT) in patients with ischemic heart disease (IHD) and reduced left ventricular ejection fraction (LVEF), the efficacy of catheter ablation in patients with nonsustained VT has been not yet clarified. The incidence of appropriate ICD therapy itself has been reported to be a worse prognostic factor in patients with reduced LVEF. Therefore theoretically the inhibition of these ventricular incidences can result in the prognostic improvement.To suppress ventricular arrhythmias aside from antiarrhythmic agents, catheter ablation has been developed prominently in this decade along with the technological improvement such as irrigated ablation catheters, three-dimensional mapping systems, multi-polar catheters, and image integration system with CT and MRI. The rationale of this trial is to study the efficacy of the eradication of arrhythmogenic substrate in ischemic cardiomyopathy with reduced LVEF and nonsustained VT on prevention of the occurrence of sustained VT/VF and ICD therapies.
Arrhythmogenic ventricular cardiomyopathy (AVC) is a genetic condition which affects the heart and can lead to heart failure and rhythm problems, of which, sudden cardiac arrest or death is the most tragic and dangerous. Diagnosis and screening of blood-relatives is very difficult as the disease process can be subtle, but sufficient enough, so that the first event is sudden death. The Mayo Clinic AVC Registry is a collaboration between Mayo Clinic, Rochester, USA and Papworth Hospital, Cambridge University Hospitals, Cambridge, UK. The investigators aim to enroll patients with a history of AVC or sudden cardiac death which may be due to AVC, from the US and UK. Family members who are blood-relatives will also be invited, including those who do not have the condition. Data collected include symptoms, ECG, echocardiographic, MRI, Holter, loop recorder, biopsies, exercise stress testing, blood, buccal and saliva samples. Objectives of the study: 1. Discover new genes or altered genes (variants) which cause AVC 2. Identify biomarkers which predict (2a) disease onset, (2b) disease progression, (2c) and the likelihood of arrhythmia (ventricular, supra-ventricular and atrial fibrillation) 3. Correlate genotype with phenotype in confirmed cases of AVC followed longitudinally using clinical, electrocardiographic and imaging data. 4. Characterize desmosomal changes in buccal mucosal cells with genotype and validate with gold-standard endomyocardial biopsies