[The long QT syndrome].

The congenital long QT syndrome (LQTS) is a hereditary cardiac disease characterized by a prolongation of the QT interval > 440 ms at rest ECG associated with a high risk of ventricular arrhythmias (torsade de pointe). Clinical manifestations are syncope and sudden cardiac death. The implicated genes encode cardiac ion channel subunits or proteins involved in modulating ionic currents. The diagnosis of LQTS can be complex in borderline cases. Etiology, pathogenesis, diagnosis and treatment are discussed.