BACKGROUND Little is known about the prevalence and prognostic significance of long QT interval among patients with chest pain during the acute phase of suspected cardiovascular injury. OBJECTIVES Our aim was to investigate the prevalence and prognostic significance of long QT interval among patients presenting to the emergency department (ED) with chest pain using an optimum QT rate correcti...

The Jervell and Lange Nielson syndrome(JLN) is an infrequent form of long QT syndrome (LQTS) in which prolonged QT interval and congenital deafness exist together. We attempted to identify patients with LQTS among 127 children (age 1.2 to 10 years) with congenital hearing loss. The corrected QT interval was measured from 12 lead electrocardiogram(ECG) , using Bazettes and Friedricia formulae.Th...

BACKGROUND Increased variability of QT interval (QTV) has been linked to arrhythmias in animal experiments and multiple clinical situations. Congenital long QT syndrome (LQTS), a pure repolarization disease, may provide important information on the relationship between delayed repolarization and QTV. METHODS AND RESULTS Twenty-four-hour Holter monitor tracings from 78 genotyped congenital LQT...

AIMS The identification of affected family members with long QT syndrome (LQTS) is often difficult due to their normal-or only marginally lengthened-QT interval duration. We examined whether physical exercise test could increase the ability to detect the mutation carrier status in phenotypically normal LQTS family members. METHODS AND RESULTS Sixty-six subjects were included: 15 were carriers...

BACKGROUND The rate-corrected QT interval (QTc) is heritable, and the discovery of quantitative trait loci that influence the QTc would be an important step in identifying the genes responsible for life-threatening arrhythmias in the general population. We studied 66 pairs of unselected normal dizygotic (DZ) twin subjects and their parents in a sib-pair analysis. We tested for linkage of gene l...

The long QT syndrome is characterized by the observed association of "torsade de pointes" and the prolongation of the QT interval on the electrocardiogram. Acquired long QT syndrome typically affects older individuals, being often associated with the action of some drugs. Hypokalemia is a frequent cause of QT lengthening on the electrocardiogram. Chronic assumption of licorice may be an unusual...

Long QT syndrome develops for a number of reasons. The number of non-antiarrhythmic drugs reported to induce QT interval prolongation with or without torsade de pointes continues to increase. Clarithromycin is a macrolide antibiotic being increasingly used for the treatment of atypical pneumonia. In this paper, we describe a patient who developed long QT prolongation syndrome after receiving cl...

AIMS Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT intervals. Here, we evaluate variability of QT intervals in patients with a history of drug-induced...

Homogeneity of recovery time protects against arrhythmias whereas dispersion of recovery time is arrhythmogenic. A single surface electrocardiographic QT interval gives no information on recovery time dispersion but the difference between the maximum and minimum body surface QT interval may be relevant. This hypothesis was tested by measuring the dispersion of the corrected QT interval (QTc) in...