View clinical trials related to Tachycardia, Ventricular.
Filter by:With the increasing use of implantable cardioverter defibrillators (ICD) for primary prevention in patients with structural heart disease, an increasing number of patients are expected to develop their first episode of monomorphic ventricular tachycardia (VT) after an ICD is in place and the only documentation of the clinical arrhythmia will be the ICD electrogram (EG). The absence of a 12-lead ECG in patients with an ICD and sustained monomorphic VT represents a limitation when performing treatment with radiofrequency (RF) ablation. The analysis of ICD-EG during a RF ablation procedure is expected to provide a reference "model" of VT with clinical expression consisting of the electrical signal of the ICD during VT (which otherwise is not generally possible to obtain in ICD patients). This will allow for a more targeted approach to the substrate of the VT with clinical expression because: 1) if VT is induced by programmed stimulation, one can tell whether it is with clinical expression or not, and 2) if VT is not induced, ventricular pacing could be performed based on the comparative analysis of morphology and activation times of ICD-EG. These approaches will result in improved outcomes of the ablation procedure.
We are investigating ways to help patients with heart failure, which is caused by damaged hearts which function less well, and cause symptoms of breathlessness, fatigue, lack of energy and swelling. Cardiac Resynchronisation Therapy (CRT) pacemakers are used to improve the pumping function of the main heart chamber in certain suitable people with heart failure. CRT requires a pacemaker with 2 wires, one placed inside the right heart chamber and one normally placed on the outside of the left heart chamber. These two wires act together to re-time the coordination of the heartbeat, which is known to improve heart function. The investigators are assessing whether they might be able to improve heart function even more by placing two wires on the inside of the left heart chamber, rather than one around the outside. The investigators wish to assess whether: 1. Using two wires within the left side of the heart gives a greater increase in heart function than one. 2. It is possible to choose the best spot inside of the heart by measuring the pattern of the heart beat. 3. Is it possible to use a different type of heart monitor placed outside the body instead of a monitor wire inside the heart to assess improvement in heart function? They are investigating this in people with hearts that beat less effectively than normal.
Ultra-high density mapping with multielectrode catheter may improve slow conduction channels identification in ventricular tachycardia substrate ablation procedures compared to conventional point by point mapping. This study compares the ability of both mapping catheters to detect slow conduction channels in areas of myocardial scar and their utility to assess substrate modification after ablation.
The investigators hypothesized that combined endocardial and epicardial VT ablation using contact sensor irrigated catheter is safe and achieves a lower recurrence rate than endocardial only ablation in ischemic and non-ischemic patients, for this the investigators will randomize 20 patients in two groups, one with endocardial only ablation and other with combined endocardial and epicardial ablation.
Heart failure with preserved ejection fraction (HFPEF) is a large medical problem, for which no drug or device has a recommendation in current heart failure guidelines. Sudden cardiac death is suggested as the most common cause of death in HFPEF patients, although data is sparse. Use of an Implantable Loop Recorder (ILR) may be useful in patients with HFPEF to evaluate the incidence of sustained ventricular tachyarrhythmias. If ventricular tachyarrhythmias are seem frequently, treatment with an Implantable Cardioverter Defibrillator (ICD) may be an option in the future.
Cardiac resynchronization therapy (CRT) is a proven therapy in patients with severe left ventricular (LV) dysfunction with ejection fraction (EF)<35%., moderate to severe congestive heart failure and wide QRS in ECG. Positive response presents as improvement in quality of life, decrease in congestive hrat failure symptoms and signs, improvements in echocardiographic measurements and longer survival. About 30% of the patients do not respond to this treatment. A decrease in clinical response to CRT is expected in patients with those predictors: advanced age, male, ischemic etiology of cardiomyopathy, Non-LBBB pattern in ECG, lack of mechanical dyssynchrony, large scar in LV, congestive heart failure stage IV, and non-cardiac co-morbidities (lung disease, pulmonary hypertension, renal failure and diabetes). There are few solutions to increase the rate of clinical response to CRT, for example: endocardial pacing of LV or pacing a few simultaneous sites on LV. A study that investigated a method of simultaneous pacing on LV of patients with congestive heart failure and LBBB with QRS>150ms has shown major improvement of cardiac contraction (increased dP/dtmax) compared to a single pacing site over a postero-basal or lateral wall site). Implantation of pacemaker leads- one in right ventricle (RV) and two over LV, i.e. multisite cardiac resynchronization therapy (MSCRT), has a few potential advantages, compared to conventional CRT.
Rationale: Sudden cardiac death, mainly caused by ventricular arrhythmias (VA), is a major cause of morbidity and mortality in non-ischemic cardiomyopathy (NICM). Therapies that effectively prevent VA are lacking. Improved understanding of the substrate and mechanisms of VA in NICM may allow more effective, individualized and substrate-based therapies to be developed. In addition, risk stratification in NICM needs to be improved so that therapies can be allocated more efficiently. Objectives: 1) To improve our understanding of the underlying pro-arrhythmic substrate and electrophysiologic mechanisms of VA in NICM, and to develop individualized treatment for VA based on the identified substrate. 2) To improve risk stratification for VA and sudden cardiac death in NICM based on substrate characteristics. 3) to evaluate disease progression in NICM. Hypothesis: Improved understanding of the substrate and mechanisms of VA in NICM may allow more effective, individualized and substrate-based therapies to be developed. Study design: A prospective cohort study. Study population: The study population will consist of three groups (A, B and C): NICM patients with documented VA, suspected VA or intermediate to high risk for VA (according to established criteria) who are not referred for cardiac surgery (group A), NICM patients with documented VA, suspected VA or a high risk for VA who are referred for cardiac surgery (group B) and a control group consisting of patients without NICM who are referred for cardiac surgery (group C). Evaluation: All patients will be evaluated according to current standards for patients with NICM. Evaluation will include 24h-Holter, echocardiography, coronary angiogram and contrast-enhanced MRI (CE-MRI). If CE-MRI is performed in another hospital, additional recordings will be performed in our hospital. Additionally, blood samples (arterial, cardiac venous and peripheral venous) for collagen turnover markers will be taken from all patients. 123-iodine metaiodobenzylguanidine (123-I MIBG) imaging, electrophysiologic study and endomyocardial biopsy will be performed in group A and B. Intra-operative biopsy will be performed in group B and C. Intervention: In group B, intra-operative mapping and cryo-ablation and postoperative electrophysiologic study will be performed in patients with subepicardial late enhancement on MRI or induced VA suspected for an subepicardial origin. Main study parameters/endpoints: The main study parameters are extent, location and pattern of fibrosis on imaging and in biopsy specimens. The main study endpoints are inducibility of VA, type of induced VA, spontaneous VA and type of spontaneous VA.
Implantable cardioverter defibrillators (ICD) may have the capacity to provoke or worsen ventricular tachyarrhythmias (VT). It has been reported that ICD shocks by itself can increase mortality. This study aimed to determine the role of back-up pacing-induced VT (PIT) to the overall ICD shock burden by avoiding pause-related ventricular back-up pacing by programming the pacing output to a sub-threshold level for ineffective pacing.
Determine effects of remifentanil conscious sedation in patients undergoing Electrophysiological (EP) studies for the ablation of idiopathic ventricular tachycardia and/or persistent frequent premature ventricular contractions (PVCs) of non-ischemic origin
The broad, long-term objective of this project is to evaluate the therapeutic value of vein of Marshall (VOM) ethanol infusion when added to catheter ablation of atrial fibrillation (AF). AF is the most common sustained arrhythmia in adults, and it is a leading cause of stroke, disability and increased mortality. Catheter ablation - pulmonary vein (PV) antral isolation (PVAI)- can lead to cure, but is best suited for paroxysmal AF, in which ectopic beats arising from the pulmonary veins were shown to initiate AF. PVAI success is lower in persistent AF, in which the role of the cardiac autonomic system, particularly the intrinsic cardiac ganglia, is being increasingly recognized. Expanding the ablation lesions to include greater areas the left atrial (LA) anatomy marginally improves outcomes, but also leads to increases in procedural complexity and duration, need of repeat procedures, and complications such as atrial flutters, particularly perimitral flutter (PMF). The investigators have developed a technique to perform rapid ablation of atrial tissues in AF using ethanol infusion in the vein of Marshall (VOM), and have shown: 1) Effective, rapid and safe tissue ablation of LA tissue neighboring the LA ridge and left inferior PV; 2) Regional LA vagal denervation by reaching the intrinsic cardiac ganglia; and 3) Facilitation of cure of PMF by ablating most of the mitral isthmus. The investigators propose to evaluate outcomes differences yielded by VOM ethanol when added to conventional PVAI. The specific aims are: #1.To assesses the impact of VOM ethanol infusion in procedure success when added to de novo catheter ablation of persistent AF. The investigators will randomize patients with persistent AF undergoing a first AF ablation to standard PVAI vs. a combined VOM ethanol infusion plus PVAI (VOM-PV) #2. To assess the impact of VOM ethanol infusion added to repeat catheter ablation of recurrent AF after a failed ablation. Patients undergoing a repeat procedure for persistent AF after a failed PVAI will be randomized to either PVAI or VOM-PV as their repeat procedure. End points will include freedom from symptomatic or electrocardiographic AF after 12-15 months.