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.
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.
Congenital long QT syndrome (LQTS) is a rare genetic disorder characterized by prolongation of the corrected QT interval (QTc) on the electrocardiogram. LQTS is associated with a risk of syncope or sudden death from ventricular arrhythmia. The increase in the duration of the corrected QT interval and / or changes in the morphology of the T wave on the electrocardiogram are markers of an increased risk of sudden death and syncope. Recently, a personal portable 6-lead device (DI, DII, DIII, aVF, aVL and aVR) connected to the patient's smartphone has entered the market (KARDIA MOBILE 6L, AliveCor, Mountain View, CALIFORNIA, USA). The APPLE WATCH Series 6 (Apple, Cupertino, CA, USA) can also record an ECG. If the device is designed to record a single lead (DI), several works have shown that it is possible to record 9 leads (DI, DII, DIII, V1, V2, V3, V4, V5 and V6) by moving simply the device (Spaccarotella CAS et al. JAMA Cardiology 2020). These devices were originally designed to screen for atrial fibrillation, but they produce accurate 6- and 9-lead ECGs and could potentially allow ambulatory ECG monitoring of patients with LQTS.
In studies, the effects of drugs used for anesthesia and analgesia on QT distance were evaluated in isolation. However, drugs are administered in combination with each other during anesthesia induction. Therefore, drugs interact in terms of positive and undesirable effects. In addition, most of the studies examining anesthesia and QT distance have been conducted in non-cardiac surgery. The target group in this study is the adult patient group who will undergo cardiac surgery. The primary aim of our study is to investigate the effect of two different types of anesthesia induction techniques on QT distance in patients undergoing open-heart surgery. QT evaluation will be performed after endotracheal intubation after anesthesia induction.
Azithromycin (AZ) is used in the pediatric group in COVID-19 diseas. It has been reported to cause prolongation in the QT interval in adult age group. The aim of this study is to evaluate the effect of AZ on ventricular repolarization in COVID-19 positive pediatric patients. METHOD The study was conducted prospectively in July-August 2020. COVID-19 pediatric patients who received AZ treatment were included in the study. ECG was obtained before treatment and on the 1st, 3rd and 5th days after the treatment. Measurements were made with Image J program®. QTmax, QTmin, Tp-emax, Tp-emin intervals were measured. QTcmax, QTcmin, Tp-ecmax, Tp-ecmin, QTcd, Tp-ecd, and QTc / Tp-ec ratios were calculated with Bazett formula.
Use lay language. Current guidelines regarding physical activity in patients with inherited arrhythmia and cardiomyopathy are mostly dedicated to adult patients, with a special focus on sports competition. Their application to the pediatric population has been scarcely evaluated. Physical activity is well known for its health benefits but may be dangerous in this population, which leads to confusion within the medical community and among patients. Actual physical activity of children with such inherited cardiac disorders is unknown. This study aimed to assess the level of physical activity in children with inherited arrhythmia and cardiomyopathy, and the adherence to the current European guidelines on the subject. Secondary objectives aimed to assess through a qualitative analysis the impact of the disease on physical activity and daily life in this population. The level of physical activity and adherence to current guidelines will be determined from interviews between the patient and the principal investigator. Each patient will be questioned in order to explore the experiences, motivations and feelings of participants regarding physical activity. The standardized questionnaire was created by the principal investigator and members of the clinical research team. The investigators believe that many children practice physical activity outside the current guidelines and hope to identify the main determinants of physical activity in this population.
Risk prediction in in inherited heart rhythm conditions that may cause sudden cardiac arrest or death is difficult. Sometimes the risks may be low but the loss of life in an otherwise healthy young individual is catastrophic. Clinicians often treat to the extreme to prevent this and so often those at unknown risk for a serious cardiac event are treated with an implanted cardioverter defibrillator (ICD) to protect against sudden death even though the risk is low or unknown. ICDs them selves are not without adverse events such as needing battery replacements, mechanical complications, inappropriate shocks and body image and self esteem issues for the patient. This study will use an inject able monitor that is less invasive to monitor inherited heart rhythm patients long term to help gather long term heart rhythm data (3 years) on patients with an inherited heart rhythm that will help to detect symptoms of dangerous heart rhythms so that the appropriate care can be provided.
The human ether-a-go-go-related gene HERG (encoding Kv11.1 potassium channels) is expressed in different parts of the body including the heart, pancreas and intestines. In the heart, Kv11.1 channels play a role in ending depolarization by causing repolarization. Loss-of-function mutations of HERG cause long QT syndrome, a condition of elongated QT interval that can lead to ventricular tachycardia, syncope and sudden death. Kv11.1 channels are also found in pancreatic α- and β-cells and intestinal L-cells, where they seem to play a role in the secretion of insulin, glucagon and Glucagon-Like Peptide-1 (GLP-1). Carriers of loss-of-function mutations in the HERG gene have showed increased insulin and incretin responses after glucose ingestion and decreased fasting levels of glucagon compared to matched control persons. Blockade of Kv11.1 has shown to augment glucose dependent insulin secretion and decrease low-glucose stimulated glucagon secretion in isolated α- and β- cells. The investigators of this study hypothesize that a blockade of Kv11.1 channels will increase incretin and β cell function and decrease α cell function and thus lead to lower glucose levels in humans after glucose intake. To investigate this, The investigators of this study will perform a randomized, cross sectional study of up to 40 healthy study participants who will serve as their own controls. The study participants will undergo two 6-hours oral glucose tolerance tests, one after intake of a known Kv11.1 blocker (moxifloxacin) and one control oral glucose tolerance test after intake of placebo. Prior to both tests the study participants will wear a continuous glucose monitor and on the day of the tests they will fill out a glucose questionnaire. Investigation of the physiological role of HERG in metabolism may provide a better insight on metabolic regulation.