long QT syndromes

long QT syndromes

a group of congenital and acquired diseases in which the electrocardiographic QT interval is longer than established measurements for age and sex; the presence of long QT intervals presages arrhythmias and sudden death.
See also: QT interval.
Farlex Partner Medical Dictionary © Farlex 2012

long QT syn·dromes

(lawng sin'drōmz)
Any of several congenital and acquired diseases in which the electrocardiographic QT interval is longer than established measurements for age and sex; the presence of long QT intervals presages arrhythmias and sudden death.
See also: QT interval
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Viskin, "Long QT syndromes and torsade de pointes," The Lancet, vol.
The long QT syndromes: Genetic basis and clinical implications.
The long QT syndromes: a critical review, new clinical observations and a unifying hypothesis.
It has new content on atrial fibrillation, implantable defibrillators, indications for pacemaker implantation, anticoagulant therapy, long QT syndromes and other channelopathies, and recently-approved anti-arrhythmia drugs.
Mutations in long QT syndromes are consistently resulting in a relative increase of depolarizing currents against repolarizing ones (Figure 1).
The congenital long QT syndromes from genotype to phenotype: clinical implications.
Beta-blockers are considered beneficial in long QT syndromes, the first choice of therapy in patients with congenital long QT (31), reduce the prevalence of cardiac events and syncope (17,32), but there is a lack of prospective, placebo-controlled studies (33).
An important cause of sudden death due to ventricular arrhythmias in apparently healthy people are the Long QT Syndromes (LQTS), which are caused by genetic mutations either in the ion channels themselves or, in some cases, other cellular processes that directly or indirectly affect the membrane potential so as to prolong repolarization (9,10).
Long QT syndromes are rare autosomal dominant inherited syndromes affecting approximately 1 in about 2500 individuals, and are produced by more than 400 different mutations (5,6).
In cases in which no structural heart disease can be identified, arrhythmias resulting from such disorders as the long QT syndromes (LQTSs) are now commonly considered to be likely causes.
Congenital and acquired long QT syndromes. Can J Cardiol 2003; 19: 76-87.