Exercise induced worsening of mechanical heterogeneity and diastolic impairment in Long QT syndrome

KCNE1 and KCNE2 variants in Patients with Long QT Syndrome

Introduction: Long QT syndrome (LQTS) is a type of ventricular arrhythmia characterized by prolonged QT intervals on electrocardiogram or delay in ventricular repolarization and it can lead to syncope, seizure and sudden cardiac death. Here, KCNE1 and KCNE2 variants are studied among Iranian affected families with this syndrome. Materials and Methods: Fifty patients referring to Rajaei Cardiov...

Drug-induced long QT syndrome.

The drug-induced long QT syndrome is a distinct clinical entity that has evolved from an electrophysiologic curiosity to a centerpiece in drug regulation and development. This evolution reflects an increasing recognition that a rare adverse drug effect can profoundly upset the balance between benefit and risk that goes into the prescription of a drug by an individual practitioner as well as the...

Evidence of genetic heterogeneity in the long QT syndrome.

Altered Na+ channels promote pause-induced spontaneous diastolic activity in long QT syndrome type 3 myocytes.

Long QT syndrome (LQTS) type 3 (LQT3), typified by the DeltaKPQ mutation (LQT3 mutation in which amino acid residues 1505 to 1507 [KPQ] are deleted), is caused by increased sodium entry during the action potential plateau resulting from mutation-altered inactivation of the Na(v)1.5 channel. Although rare, LQT3 is the most lethal of common LQTS variants. Here we tested the hypothesis that cellul...

Rate adaptation of QT intervals during and after exercise in children with congenital long QT syndrome.

OBJECTIVES To improve the diagnostic criteria of the congenital long QT syndrome in borderline cases we examined rate adaptation of ventricular repolarization phases during exercise and subsequent recovery in children with the long QT syndrome and controls. METHODS Nineteen children with definite long QT syndrome and 19 healthy controls underwent exercise testing. QT intervals were measured t...