View clinical trials related to Long QT Syndrome.
Filter by:QT interval, defined as the time between the beginning of the QRS complex and the end of the T wave in electrocardiography (ECG), is an indicator of depolarization and repolarization of the myocardium.11 Prolongation of the heart rate corrected QT (QTc) interval reflects electrical instability of ventricles and is associated with life-threatening ventricular arrhythmias, including torsade de pointes, ventricular fibrillation and sudden cardiac death. Spinal anesthesia can cause profound prolongation of the QTc interval due to disparity between lumbar and thoracic sympathetic activity following subarachnoid block. Meanwhile inhalational anesthetics, sevoflurane, isoflurane, and desflurane are known to prolong QTc interval and intravenous anesthetics such as propofol, thiopental, etomidate and ketamin can also cause remarkable prolongation of the QTc interval. Moreover laryngoscopy and intubation may contribute to prolongation of the QTc interval because of the sympathetic stimulation. Over the years it has been occurred an increase in the proportion of elderly population requiring surgical anesthesia. The incidence of ventricular arrhythmias increases in advancing age even in the absence of underlying heart disease and elderly patients have reduced physiological functions and poor tolerance to anesthesia. However the choice of anesthesia type is critical in this population. To the best of knowledge, there was no published study to compare spinal anesthesia and inhalational anesthesia in elderly patients with regard to the QT interval changes. Investigators aimed to investigate the effects of spinal anesthesia on QT, QTc intervals and to compare general anesthesia with sevofluran in elderly patients.
Cardiac channelopathies induce severe heart rhythm or conduction disorders. Mutations of the KCNH2 gene, that encodes the human (h) ERG channel, is responsible for 30-40% of all cases of long QT syndrome (inherited LQT2). Besides, hERG is frequently responsible for off-target effects of several pharmacological agents (acquired LQT2). With the advent of Next Generation Sequencing, hundreds of new KCNH2 variants are accumulating in regional databases including those developed by french centers of references. Worldwide, we estimate there are more than 1000 variants for hERG channel. Unfortunately, many of these new variants appear to be of unknown functional significance in spite of available clinical and genetic information. Little is known on whether they affect the channel biophysical properties, its expression at the cell surface and/or its structure. Yet, this information is crucial to determine the real degree of pathogenicity of these variants, and therefore to make the proper diagnosis on inherited LQT2, counsel the patient for his treatment and improve the management of the patient's life. Our ambition is therefore to tackle this issue of variant significance by (i) launching a large-scale multi-functional evaluation of hERG variants, (ii) introducing for the first time a formatted large-scale pathogenicity annotation score for all variants that have been functionally evaluated by this multi-parametric approach, and (iii) regrouping all the relevant information collected in every French Regional centers of reference into a single National database hosted by an infrastructure that possesses enough flexibility for continuous data implementation and cross-referencing. The database will integrate the latest International guidelines for functional pathogenicity annotation. This project will also include the pharmacological characterization of several drugs susceptible to produce acquired LQT2 with variable severities. We aim to understand whether there are structural regions within hERG channel in which the introduction of a variant is more prone to increase the risk of acquired LQT2 or if, on the contrary, a set of variants may relatively protect some patients against LQT2-inducing drugs.
Children and adolescents with inherited cardiac arrhythmia su ch Long QT Syndrome (LQTS) have lower physical and quality of life than their healthy peers. A multi-component cardiac rehabilitation, including an exercise training program and education program, might counteract those effects. The goal of this pilot study is to evaluate the security, feasibility, and benefits of a cardiac rehabilitation program in children with LQTS aged between 6 to 18 years old. The main question[s] it aims to answer are: - Is center-based cardiac rehabilitation safe and feasible for children with LQTS? - Does a 12-week cardiac rehabilitation program improve physical fitness and quality of life?
Part 1: This is a Phase 1b, randomized, double-blind, crossover, dose escalation, placebo-controlled study to evaluate the effect of oral LQT-1213 on dofetilide-induced QTc prolongation in healthy adult subjects. This is a 2-treatment, 2-period crossover study with approximately up to 28 healthy subjects, with screening procedures within 28 days of enrolment. Part 2: This is a Phase 2a, single-blind, placebo run-in, multiple-dose safety study to evaluate the safety, tolerability, and PK of LQT-1213 in patients diagnosed with LQT2 or LQT3. Up to 12 participants with LQT2 and up to 12 participants with LQT3 will be recruited.
"Chang Gung ECG Abnormality Detection Software" is a is an artificial intelligence medical signal analysis software that detect whether patients have abnormal ECG signals of 14 diseases by static 12-lead ECG. The 14 diseases were - Long QT syndrome - Sinus bradycardia - Sinus Tachycardia - Premature atrial complexes - Premature ventricular complexes - Atrial Flutter, Right bundle branch block - Left bundle branch block - Left Ventricular hypertrophy - Anterior wall Myocardial Infarction - Septal wall Myocardial Infarction - Lateral wall Myocardial Infarction - Inferior wall Myocardial Infarction - Posterior wall Myocardial Infarction The main purpose of this study is to verify whether "Chang Gung ECG Abnormality Detection Software" can correctly identify abnormal ECG signals among patients of 14 diseases. The interpretation standard is the consensus of 3 cardiologists. The results of the software analysis will be used to evaluate the performance of the primary and secondary evaluation indicators.
This is a single-center, randomized, double-blind, placebo-controlled study to be conducted in 2 parts: single ascending dose (SAD) incorporating a food effect arm and multiple ascending dose (MAD). Potential participants for each part will undergo screening procedures within 28 days of enrollment.
QT interval prolongation occurs in athletes and causes concerns, as it may indicate the life-threatening long QT syndrome (LQTS). Clinical and genetic testing identify those clearly affected by LQTS but in many no disease-causing mutations are found and diagnosis remains uncertain while they are barred from competitive sports. The investigators hypothesize that several cases represent an acquired form of LQTS, akin to drug-induced LQTS, caused by exercise training acting as a trigger or "second hit" on a genetic predisposition. The investigators will use next generation sequencing to screen major and minor LQTS genes plus common and rare variants modulating the QT interval in athletes with a QTc>450ms (cases) and in those with a QTc<430ms (controls). Thus, the investigators will quantify the presence of LQTS in athletes and will also focus on those who normalize their QTc after detraining, as this points to activation of stretch-receptors. The investigators will clarify QT prolongation in athletes and contribute to correct diagnosis.
Since 2005, FDA has required almost all new drugs be tested for their ability to prolong the QT interval through clinical studies. This requirement stems from the increased TdP risk QT interval prolongation can cause. However, the QT interval is an imperfect biomarker, as there are multiple drugs that can prolong the QT interval, without causing increased TdP occurrence. As such, numerous drugs labeled as causing QT prolongation, may in fact have no impact on TdP occurrence. To address this problem, FDA, in collaboration with multiple external partners, has led an initiative to combine novel preclinical in vitro experiments within silico modeling and simulation followed by pharmacodynamic electrocardiographic (ECG) biomarkers. The goal is to use these novel computational and analytical tools to better predict TdP risk (beyond just the QT interval) by focusing on understanding the underlying mechanisms and applying an integrated biological systems approach. This clinical study consists of 2 parts: a 3-arm, 22-subject crossover study (Part 1) and a 4-arm, 22-subject crossover study (Part 2). These parts are included in the same protocol and study due to the similarity of the inclusion and exclusion criteria, similar procedures, and similar primary goals.
The "Long-term Outcome and Predictors for Recurrence after Medical and Interventional Treatment of Arrhythmias at the University Heart Center Hamburg" (TRUST) study is an investor-initiated, single-center, prospective clinical cohort study including patients treated with cardiac arrhythmias or at high risk for cardiac arrhythmias. The design enables prospective, low-threshold, near complete inclusion of patients with arrhythmias treated at the UHZ. Collection of routine follow-up data, detailed procedural information and systematic biobanking will enable precise and robust phenotyping.
An important aspect of successful genomic medicine implementation is developing effective approaches for screening at-risk family members after probands are identified, also known as cascade screening. Most cascade screening studies conducted to date have been conducted outside the US, and very few studies have used a rigorous approach involving a comparator group or randomized controlled design. A major question in the field is how to most effectively implement cascade screening, given commonly cited communication barriers, while respecting privacy among probands and family members. This study will conduct a randomized controlled trial to assess direct contact of relatives by study team members vs indirect, or proband-initiated, contact. We will assess efficacy of the cascade screening intervention, patient-centered outcomes regarding mental, physical, and psychosocial outcomes in probands and family members, and implementation evaluation outcomes. Individuals who are known to carry the KCNQ1 Met224Thr or APOB Arg3527Gln variant will be eligible to participate. After providing consent and being deemed eligible, individuals will be randomized in a 1:1 manner into the direct or indirect contact of family members arm of the study. The randomization will be stratified by variant to ensure equal representation of each variant in the study arms. Individuals in the indirect arm will be instructed to contact their first-degree family members about the opportunity to be screened. They will be provided with a disease-specific pamphlet and a family letter explaining the cascade screening. In the direct arm, probands will be advised that the study staff will be contacting their family members. They will be instructed to also contact their family members prior to the study team contacting them. Approximately two weeks after this meeting with the proband, the study staff will mail letters to eligible first-degree family members of the probands. If we do not hear back from individual family members, we will follow-up with another letter, telephone call, or home visit. The information contained in the letters will be the same information for both the direct and indirect arms of the study. All interested family members will receive pre-test counseling and free, in-home, saliva-based genetic testing, and post-test counseling.