Long QT Syndrome

Risks

People at risk of long QT syndrome include:

• Children, teenagers and young adults with unexplained fainting, near drownings or other accidents, seizures or a history of cardiac arrest
• Family members of children, teenagers and young adults with unexplained fainting, unexplained near drownings or other accidents, unexplained seizures or a history of cardiac arrest
• Relatives of persons with known long QT syndrome
• Children who are deaf at birth
• Children and young adults who have unexplained sudden death in family members
• People taking medications known to increase the risk for LQTS
• People with low potassium, magnesium, or calcium in their blood — such as those with the eating disorder anorexia nervosa — may be susceptible to prolonged QT intervals

Researchers believe that long QT syndrome may be responsible for hundreds of otherwise unexplained deaths in children and young adults each year in the United States. For example, an unexplained drowning of a young person may be the first clue to inherited long QT syndrome in a family.