Definition:

Long QT syndrome (LQTS) is a cardiovascular disorder resulting from mutations in cardiac ion channels. LQTS is characterized by prolongation of the QT interval in the electrocardiogram (ECG) and a propensity to torsades de pointes ventricular tachycardia frequently leading to syncope, cardiac arrest, or sudden death usually in young otherwise healthy individuals. Anesthesia in a patient with LQTS can trigger malignant arrhythmias and is therefore a high-risk procedure. There are two well-known syndromes with a long QT interval. The Romano-Ward syndrome is characterized by an autosomal-dominant inheritance without familial deafness. The Jervell and Lange-Nielsen syndrome (JLNS) has an autosomal-recessive pattern of inheritance and is associated with deafness.