View clinical trials related to Long QT Syndrome.
Filter by:The drug-induced long QT syndrome (diLQTS) describes a clinical entity in which administration of a drug produces marked prolongation of the QT interval of the electrocardiogram, associated with the development of a polymorphic ventricular tachycardia, termed torsades de pointes (TdP). The heart rate is an important variable affecting the QT interval. The QT interval normally shortens as the heart rate accelerates; however, the adaptation of the QT interval to sudden heart rate acceleration is not instantaneous. Interestingly, Holter studies show that the speed of response of the QT interval to sudden changes in heart rate (that is, the time it takes the QT interval of a given person to reach a new steady-state QT/RR relation) in healthy persons is highly individual and independent of the basic QTc. The investigators and others recently proposed the "quick standing" test as a simple bedside test that facilitates the diagnosis of congenital LQTS. The test takes advantage of the fact that as one stands up, the heart rate acceleration is abrupt while the associated QT-interval shortening is gradual. As the R-R interval shortens faster than the QT interval, the QT appears to "stretch" toward the next P wave and the corrected QT interval (QTc) for heart rate actually increases momentarily. The phenomenon of "QT stretching" is universal but is exaggerated in patients with LQTS, allowing for a simple but accurate diagnostic test. There is no data on the effects of quick standing on drug-associated form of the long QT syndrome. The investigators therefore propose the present study to better understand who these patients with drug-associated form of the long QT syndrome are and what the significance of their abnormal QT-response is.
The goal is to determine how lifestyle and exercise impact the well-being of individuals with hypertrophic cardiomyopathy (HCM) and long QT syndrome (LQTS). Ancillary study Aim: To understand how the coronavirus epidemic is impacting psychological health and quality of life in the LIVE population
Torsades de pointes (TdP) is a potentially fatal ventricular arrhythmia associated with corrected QT (QTc) interval prolongation. More than 50 commonly used drugs available on the US market may cause QTc interval prolongation and TdP. While TdP occurs more commonly in women, 33-45% of all cases of TdP have occurred in men. Older age is a risk factor for drug-induced TdP in men, possibly due to declining serum testosterone concentrations. Available evidence shows an inverse relationship between QTc intervals and serum testosterone concentrations. In addition, experimental data, including those from the investigators' laboratory, suggest that both exogenous testosterone or progesterone administration may be protective against prolongation of ventricular repolarization and TdP. Specific Aim: Establish the influence of transdermal testosterone administration and oral progesterone administration as preventive methods by which to diminish the degree of drug-induced QT interval prolongation in men 65 years of age or older. Hypothesis: Transdermal testosterone administration and oral progesterone administration both effectively attenuate drug-induced QT interval response in older men. To test this hypothesis, transdermal testosterone, oral progesterone or placebo will be administered in a 3-way crossover study to men 65 years of age or older. QTc interval response to low-dose ibutilide will be assessed. The primary endpoints will be Fridericia-corrected QT interval (QTF) response to ibutilide, in the presence and absence of testosterone, and in the presence or absence of progesterone: 1) Effect on pre-ibutilide QTF, 2) Effect on maximum post-ibutilide QTF, 3) Effect on % change in post-ibutilide QTF, and 2) Area under the QTF interval-time curves.
This study will evaluate the pharmacokinetics (PK), safety, and tolerability of a single oral dose of eleclazine and its metabolite, GS-623134, in participants with normal and impaired renal function. Participants in the healthy control group will be matched to participants with impaired renal function by age (± 5 years), gender, and body mass index (± 10%).
The NLQTS Research Network team aims to build a Canadian collaboration of dedicated investigators that will create a new paradigm in the modern investigation of patients with LQTS and in the description of a new disease modifier. The project aims to describe the natural history of familial Long QT Syndrome to identify: 1. Low risk patients that do not require protective beta-blocker therapy 2. High-risk patients that require protective beta-blocker therapy and may benefit from a primary prevention ICD. This cohort would contain treated pre-symptomatic individuals effectively protected from harm.
The primary objective of this study is to evaluate the pharmacokinetic (PK) profile of oral eleclazine and its metabolite, GS-623134, in participants with normal and impaired hepatic function. Participants in the healthy control group will be matched to participants with impaired hepatic function by age (± 5 years), gender, and body mass index (± 10%).
This study will evaluate the effect of oral GS-6615 on QTc interval in healthy adults with dofetilide-induced QTc prolongation.
The primary objective of the study is to evaluate the effect of oral eleclazine (formerly GS-6615) on corrected QT (QTc) interval in participants with long QT2 syndrome.
The primary objective of this research study is to test the hypothesis that late sodium current blocking drugs (mexiletine or lidocaine) can attenuate the effect of hERG potassium channel blocking drugs (dofetilide) on ventricular repolarization (QTc) by shortening early repolarization (J-Tpeakc). The secondary object is to assess the ability of calcium channel block (diltiazem) to reduce the QTc prolongation associated with hERG block (moxifloxacin).
The purpose of this study is to determine the true incidence of long QT (LQT) amongst a large cohort of subjects diagnosed with unilateral (right/left) or bilateral sensorineural hearing loss.