Dangerous and life-threatening drugs - practical lessons from the long QT syndrome.

The long QT syndrome (LQTS) is caused by delayed cardiac repolarisation and may be associated with ventricular arrhythmias (torsades de pointes) and sudden death. The congenital LQTS is caused by mutations in any one of many genes coding for ion channels responsible for cardiac repolarisation. The acquired LQTS is much more common and may be associated with various metabolic conditions, acquired heart disease or drugs.