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Long QT syndrome (LQTS)

LQTS is a condition that affects the electrical activity of your heart. It can cause an abnormal heart rhythm, known as an arrhythmia. Arrhythmias can occur during exercise, stress, and fever or after loud noises. This abnormal heart rhythm can lead to a sudden fainting spell or a seizure. If the arrhythmia continues for a long period of time, it can cause sudden death.

What are the symptoms of LQTS?

  • Fainting, including dizziness, racing heart (palpitations) and blurred vision
  • Seizures
  • Cardiac arrest
  • Sudden death

What causes LQTS?

LQTS can be inherited or acquired. Inherited LQTS means that there is a change in your DNA that causes LQTS. Acquired LQTS can occur when you take certain medications. The list of medications that are associated with acquired LQTS can be found on www.sads.org.

How is LQTS diagnosed?

  • Electrocardiogram (EKG or ECG), a test that measures the electrical activity of your heart
  • Exercise EKG, also known as a stress test, measures the electrical activity of your heart while you exercise on a treadmill or stationary bike
  • Holter monitoring, which is a continuous way to monitor your heart rhythm over 24 hour periods or longer
  • Genetic testing, a blood test to find a change in your DNA that causes LQTS

How is LQTS treated?

Treatment of LQTS involves treating the arrhythmia, or abnormal heart rhythm. This treatment can include medication, surgery or an implantable device. It is important to discuss with your physician what medications should be avoided when you have LQTS, to prevent triggering an arrhythmia.