Evaluation of a Patient with a Positive Family History for Long QT Syndrome.

The hereditary long QT syndrome (LQTS) is a genetic channelopathy that is associated with increased propensity for polymorphic ventricular tachyarrhythmias and sudden cardiac death in young individuals with normal cardiac morphology. The diagnosis of this genetic disorder relies on a constellation of electrocardiographic, clinical, and genetic factors. Beta-blockers are the mainstay therapy in LQTS, whereas implantation of a cardioverter defibrillator is generally reserved for secondary prevention or for those who remain symptomatic on beta-blocker therapy. Herein we present a case that demonstrates important diagnostic and management dilemmas among patients who have a positive family history of LQTS.