Long QT syndrome

Long QT syndrome (LQTS) is characterised by a prolonged QT interval on ECG, which may be congenital or acquired.

In congenital LQTS, genetic mutations affect ion channels important in myocardial repolarisation.

Acquired LQTS may occur secondary to ingestion of QT interval-prolonging drugs, electrolyte imbalances, or bradyarrhythmias.

Patients with LQTS are at increased risk of syncope, ventricular arrhythmias (including torsades de pointes), and sudden cardiac death.

Unless there is an identifiable reversible cause, treatment primarily involves lifestyle modification and beta-blocker therapy with the implantation of a cardioverter-defibrillator in selected cases.

Long QT syndrome (LQTS) is a congenital or acquired condition that is characterised by a prolonged QT interval on the surface ECG and is associated with a high risk of sudden cardiac death due to ventricular tachyarrhythmias. In congenital LQTS, mutations within 15 identified genes result in a variety of channelopathies affecting myocardial repolarisation, thus prolonging the QT interval.