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.
The congenital long QT syndromes from genotype to phenotype: clinical implications.
Long QT syndrome (LQTS) is an uncommon cardiac disorder of repolarisation leading to prolonged QT interval and T wave abnormalities in the ECG, thus predisposing to Torsades de Pointes (TdP).
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.
INTRODUCTION: The
long QT syndrome has aroused considerable interest in the medical community since its first description by Jervell-Lange in congenitally deaf children and later independently by Romano and Ward in persons with normal hearing.
It is a sub-variant of
long QT syndrome, which is a heart condition that causes cardiac muscle to take longer than usual to recharge between beats characterized by prolonged QT interval on an electrocardiograph (ECG) and associated with a high risk for syncope, fits and sudden death.
Mutations in the hminKgene cause
long QT syndrome and suppress IKs function.
Torsade de pointes is a form of polymorphic ventricular tachycardia that occurs in the setting of both congenital and acquired
long QT syndrome (LQTS) (9).
T wave morphology was defined as in the congenital
Long QT syndrome (LQTS): 1) "LQT1-like morphology" denoted a long QT interval (QTc interval [greater than or equal to] 450 ms) with broad T waves; 2) "LQT2-like morphology" denoted a long QT interval with double (notched) T waves; and 3) "LQT3-like morphology" denoted a long QT interval with small T waves separated from the (IRS interval by a long isoelectric ST-segment (12, 13).
