Risk factors

The following things may increase your risk of developing congenital or acquired long QT syndrome or its symptoms:

• A history of cardiac arrest
• Having a first-degree relative (parent, sibling) with long QT syndrome
• Using medications known to cause prolonged QT intervals
• Being female and on heart medication
• Excessive vomiting or diarrhea
• Eating disorders, such as anorexia nervosa, which cause electrolyte imbalances

Sexual intercourse doesn't appear to be high risk for patients with long QT syndrome. Pregnancy and delivery aren't associated with an increased risk of symptoms in women diagnosed with long QT syndrome. However, if you have the condition and are pregnant, your doctor will want to carefully monitor you during and after pregnancy.