View clinical trials related to Long QT Syndrome.
Filter by:The purpose of this study is to learn what effect rapid atrial pacing (in patients with dual chamber pacemakers) will have on the electrocardiogram including the QT Interval. The investigators are also interested in the differences caused by genes.
Background. In congenital long QT syndrome type 1 (LQT1), episodes of ventricular tachycardia are usually triggered by exercise and can be prevented in most patients by beta-blocker therapy. In addition, LQT1 associated with a normal resting QT interval can be unmasked by the abnormal QT response to exercise testing (failure of the QT interval to shorten normally). Preliminary data from our laboratory show that the exercise QT intervals of patients with LQT1 are partially normalized by beta-blocker therapy. It is still currently not known if beta-blockers modify the QT/heart rate relationship (a primary effect on repolarization) or if the "normalizing" effect is due to the inability of subjects on beta-blockers to attain sufficiently high workloads (due to reduced heart rate) for prolongation to occur. Moreover, the physiologic response of the exercise QT interval to beta-blockers in healthy control subjects is not known. Objective. The objective of this study is to define the impact of beta-blocker therapy on the QT response to exercise and recovery in normal subjects. Methods. Approximately 36 healthy adult subjects age-matched to previously studied LQT1 subjects will undergo 1) screening history, 2) two weeks of beta-blocker therapy ending in an exercise test, and 3) two weeks of placebo therapy ending in an exercise test. Beta blocker and placebo will be given in random order in a double-blind fashion. The QT response to exercise and recovery will be compared between drug-free and beta-blocker-treated states. These data will be compared to those previously collected for LQT1 subjects. Implications. These results will provide new information about the effect of beta-blocker therapy on repolarization parameters in normal subjects, and will provide a context in which to interpret the previous findings that beta-blocker administration modifies the QT response to exercise in LQT1 subjects.
Long QT Syndrome (LQTS) is a disease of young adults and can affect women of child bearing age. Suffers of LQTS are at risk of ventricular dysrhythmias including torsades de pointes and ventricular fibrillation. Pregnancy increases the chance that any mother may have an abnormal heart rhythm or arrhythmia. This chance is higher with the LQTS. There are only a few reported cases of women with the LQTS having a baby in the medical literature. This can make it difficult for the doctor caring for a pregnant woman with the long QT syndrome - especially should they need an anesthetic. We would like to study as many women who have had a baby who have the long QT syndrome to give us a better idea of whether there are any arrhythmias occurring at the time of delivery.
The purpose of this study is to collect surface electrograms from standard and several non-standard configurations in patients with long QT syndrome, heart failure, cardiac resynchronization therapy or wide QRS during a routine outpatient assessment. The ECGs collected will be used as test signals by the sponsor for the development of a subcutaneous implantable defibrillator
This is a randomized, prospective clinical trial comparing 2 different types of implantable cardioverter defibrillator (ICD) leads in children and patients with congenital heart disease. ICD lead survival in this patient group is particularly suboptimal, and lead extraction is technically difficult and carries a substantial morbidity risk. Recently, improved ICD lead designs have been released and are currently being utilized in patients. The main aim of the study is to determine if either type of lead performs better in terms of implantation electrical characteristics, long-term survival without breaking, and ease of extractability.
To assess the effect of ERB-041 after multiple oral doses on cardiac repolarization as assessed by the QTc interval.
The CASPER will collect systematic clinical assessments of patients and families within the multicenter Canadian Inherited Heart Rhythm Research Network. Unexplained Cardiac Arrest patients and family members will undergo standardized testing for evidence of primary electrical disease and latent cardiomyopathy along with clinical genetics screening of affected individuals based on an evident or unmasked phenotype.
The aim of this study is the identification of familial congenital arrhythmogenic disorders and their clinical follow-up.
To conduct a cross-sectional epidemiologic study of the determinants of prolonged heart rate corrected QT interval (QTc) among 300 men and 300 woman in the population with the highest known risk of SUDS: Southeast Asian refugees in Thailand. .
To screen by electrocardiography the entire population of 1,400 individuals in seven Amish Mennonite communities in order to perform genetic linkage studies of long QT syndrome (LQTS).