Long QT syndrome: a preventable cause of sudden death in women.

Long QT syndrome is a hereditary disorder of cardiac ion channels causing abnormal electrical activation of the heart and leading to life-threatening ventricular tachycardia. Syncope, ventricular tachycardia, or sudden cardiac death in the absence of structural heart disease is the typical presentation, often starting in childhood. Women are more commonly affected by both the congenital form and the drug-induced acquired form of this disease and are particularly at risk in the postpartum period. The long QT syndrome can be recognized by a prolonged QT interval on the electrocardiogram. Several mutations in six genes encoding subunits of cardiac potassium and sodium channels have so far been identified, and gene-specific epidemiology, risk stratification, and management are emerging. beta-blockers are the mainstay of therapy for primary prevention of cardiac events and implantable defibrillators for secondary prevention. Patient education, screening of family members, and increasing awareness of this disorder among physicians are important steps toward prevention of sudden death in these otherwise healthy young individuals.