View clinical trials related to Tachycardia.
Filter by: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.
The purpose of this clinical investigation is the continued assessment of the decision accuracy of St. Jude Medical (SJM) ICD with enhanced SVT discriminators in the treatment of subjects with primary and secondary prevention of sudden cardiac death.
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.
Use of dipole density mapping to identify activation in complex supraventricular tachycardias
Use of dipole density mapping to identify activation in complex supraventricular tachycardias
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.
In this study, the investigators aim to examine the prognostic role of subsequent Atrial Tachycardias (ATs) in the mechanisms of atrial fibrillation (AF). Therefore, the investigators compare patients who were randomly assigned to either undergo cardioversion after AF has been terminated to AT or further ablation until the achievement of sinus rhythm.