View clinical trials related to Tachycardia.
Filter by:Each year in the UK, approximately 150,000 people have a heart attack when the blood supply to their heart is compromised. As a result, affected regions of the heart can become diseased and scarred. In a healthy person, electrical waves propagate across the heart in a regulated pattern which triggers contraction to pump blood around the body. The scar tissue that forms as a result of a heart attack can disrupt the propagation of the electrical waves. If significant disruptions occur, blood cannot be pumped out of the body effectively, leading to sudden death. Ablation therapy aims to eliminate areas of diseased tissue that cause disruption to the heart rhythm, by applying radiofrequency using catheters inserted into the heart. The most accurate techniques used to locate the region to ablate require the induction of dangerous heart rhythms, which are only inducible in about 65% of people. Pace mapping is a technique used to locate regions to ablate, which can be performed during normal heart rhythm. ECG data, which records electrical signals from the heart, is collected when the patient has an abnormal heart rhythm. From this template ECG, a clinician can tell the approximate location of the diseased tissue. A catheter is directed to that location, the heart stimulated, and another ECG, called the paced ECG is recorded. If the paced ECG matches the template ECG, it is assumed that the heart was paced in the location that requires ablation. Current ablation techniques are difficult, time consuming, and inaccurate. As a result, the procedure may work in only half of all patients, and result in unnecessary damage to healthy tissue, leading to later impairment of heart function. The CPS project's overall goal is to increase the success rates of ablation therapy by improving the accuracy and efficiency of locating the optimal region of tissue to eliminate during the pace mapping procedure. Increasing ablation therapy success rates will mean that patients will be unlikely to suffer from future heart rhythm disorders as a result of their heart attack, increasing the life expectancy of heart attack patients. Excess damage caused to the heart as a result of unnecessary ablation lesions will be limited, decreasing the likelihood of future complications. In addition, dangerous heart rhythms do not need to be induced in the patient, significantly decreasing the risk of death during the treatment.
STereotactic Ablative Radiosurgery of recurrent Ventricular Tachycardia in structural heart disease (STAR-VT).
This study is an observational study without any hypothesis testing. It intended to observe the clinical application of electrophysiological mapping and catheter ablation of atrial tachycardia post atrial fibrillation ablation or cardiac surgery guided with Rhythmia System.
POTS is a relatively common condition that affects millions of patients around the globe. It has an estimated prevalence of 170/100,000 with approximately 80% of patients being women of childbearing age. POTS is characterized by an excessive heart rate increase on assuming an upright posture, either standing or even sitting and leading to disabling palpitations, light-headedness, and even in syncope in severe cases. More than 95% patients with POTS have pronounced cardiovascular deconditioning and show marked exercise intolerance. The severity of POTS is variable. In mild cases the affected patient may continue with routine activities with minimal limitations. Severe form of the disease precludes most normal life activities, such as sitting upright, walking or standing to perform even basic house chores. An estimated 40% of patients with POTS have a resistant form of the condition that is nonresponsive or mildly responsive to all treatments resulting in continued functional limitations in the long term. Many of the currently available treatments in POTS are geared towards increasing blood pressure. These include compression stockings, increased daily fluid intake and increased salt ingestion. Saline infusions may be helpful in certain patients in the short term, though many do not respond. The effectiveness of medications varies greatly, with many patient failing to improve. A small series of clinical patients suffering from severe POTS have shown robust response to weekly albumin therapy, which supports the hypothesis that periodic albumin infusions will provide significant and sustained symptomatic relief to patients with severe POTS. This pilot study will explore the effectiveness of albumin infusions as a treatment for POTS. Eligible patients will receive weekly intravenous infusions of 5% Albumin or Saline in a double blinded fashion for 4 weeks and will crossover to the other infusion for 4 weeks after an intervening 4-week washout period. The participants will be required to maintain a daily diary of their symptoms during the screening, the study and washout periods. Any possible adverse effects as the result of infusions will be documented. Outcome measures will be quantified and validated at the end of each study period and the percentage reduction of tachycardia will be determined at the completion of each study arm.
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.
This proposal aims to evaluate safety and efficacy aspects of a new protocol for AVNRT ablation, using a stepwise anatomical approach. The investigators hypothesize that the use of a standardized electro-anatomical guided strategy, using a sequential approach as follows: 1. Right-side postero-septal tricuspid annulus 2. Coronary sinus 3. Left-side postero-septal mitral annulus For slow pathway AVNRT ablation is safe and efficient, increasing the chance of a successful ablation in difficult cases, while reducing the need of re-do procedures and the risk for high-degree atrio-ventricular block. The investigators aim to define and implement a new standardized protocol for AVNRT ablation while at the same time assessing the efficacy and safety of coronary sinus and left-side approaches for slow-pathway 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.