View clinical trials related to Long QT Syndrome.
Filter by:The purpose of this study is to validate the continuous patch monitoring system to evaluate cardiac arrhythmias in patients receiving drugs that can cause cardiac complications and compare the continuous patch system with standard electrocardiograms (ECGs).
The goal of this research is to prospectively evaluate the performance of the electromechanical window according to a phonographic method, as a mean of diagnosis of long QT syndrome, and to compare its performance with routine tests used.
The Hearts in Rhythm Organization (HiRO) is a national network of Canadian researchers/clinicians, working towards a better understanding of the rare genetic causes of sudden cardiac death (SCD). Canadian adult and pediatric electrophysiology centres across Canada work together to gather data and bio sample in a national data registry and bio bank hoping to improve the detection and treatment of inherited heart rhythm disorders to prevent sudden death.
The goal of this study is to determine whether anti-Ro/SSA antibodies are associated with acquired QT prolongation in subjects with connective tissue disease. The investigators will investigate whether gender or race influence correlation between anti-Ro antibody status and prolonged QT interval and the role of inflammatory cytokines in association with anti-Ro antibodies and QT prolongation. The investigators propose to add an additional objective to test whether QT prolongation is reversible with moderate doses of prednisone in patients with QT interval greater than 500 msec.
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.
High-resolution, non-invasive electromechanical mapping in genotyped long-QT syndrome patients and healthy controls at baseline and during smart provocation.
A number of drugs used in the perioperative period may cause prolongation of the QT interval on the electrocardiogram (EKG). These drugs include inhalational agents, antiemetic agents, pain medications, and drugs used to reverse the effects of muscle relaxants. Approximately 80% of patients undergoing a general anesthetic will demonstrate significant prolongation of the QT interval on the EKG in the postanesthesia care unit (PACU) following surgery. The concern with QT interval prolongation is that it can result in a potentially lethal ventricular arrhythmia termed torsade des pointes. Despite the concurrent use of several of these medications in a typical general anesthetic, torsade des pointes is a rare event in the perioperative period. In the past decade, the use of intravenous methadone as part of a balanced anesthetic technique has increased significantly. A single dose provided at induction of anesthesia can provide prolonged (24-48 hours) relief from pain. Studies in patients receiving long-term treatment with methadone for addiction therapy or chronic pain have revealed that these patients are at risk for QT prolongation, torsade des pointe, and cardiac death. However, the effect of a single intravenous dose of methadone used in the operating room on the QT interval is uncertain. The aim of this randomized clinical trial is to compare the impact of methadone, when compared to the more commonly-used opioid hydromorphone, on QT prolongation measured with a 12-lead EKG in the PACU and on postoperative day 1. We hypothesize that methadone will not result in significant QT prolongation when used as part of a standardized general anesthetic.
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.
This research will determine if oral progesterone attenuates drug-induced QT interval lengthening in a) Postmenopausal women 50 years of age or older, and b) Premenopausal women studied during the ovulation phase of the menstrual cycle. This investigation will consist of two concurrent prospective, randomized, double-blind, placebo-controlled crossover-design studies in a) Postmenopausal women, and b) Premenopausal women. Each subject will take progesterone or placebo capsules for 1 week. After a two-week "washout" (no progesterone or placebo) each subject will then take the alternative therapy (progesterone or placebo) for 1 week. After 7 days of each treatment, subjects will present to the clinical research center to receive a small dose of the QT interval-lengthening drug ibutilide, and the effect on the QT, J-Tpeak and Tpeak-Tend intervals during the progesterone and placebo phases will be compared
The objectives of the protocol are to: (1) evaluate the uptake of cascade screening and preventative therapies after the implementation of a simplified screening process and (2) assess proband and family member perspectives about the return of research results and cascade screening for the KCNQ1 Thr224Met variant. The investigators will conduct a mixed methods study in the Old Order Amish community where the KCNQ1 variant is enriched over 100,000-fold compared to other populations. The intervention will offer free, mail-in, saliva-based genetic testing for family members of probands. The rate of uptake of testing and preventative therapy after the intervention is implemented (i.e. when 'simplified' free, mail-in, saliva-based testing was available) will be compared to data from before the intervention (i.e. when 'traditional' $50 blood-based testing was available to family members) when uptake was essentially zero. The primary outcome is the rate of uptake of cascade screening with the intervention ('simplified'). The secondary outcomes include: extent of disclosure of genotype results before and after the intervention, proportion of informed relatives who get screened before and after the intervention, and the uptake of appropriate preventative care (e.g. seeing a cardiologist and/or taking beta-blocker). The tertiary outcomes are demographic characteristics associated with uptake of cascade screening or uptake of preventative therapy. The investigators will also assess qualitative themes surrounding the return of results process and cascade screening using interviews.