Short QT Syndrome

What is short QT syndrome (SQTS)?

SQTS is a condition that affects the electrical activity of your heart. It can cause an abnormal heart rhythm, known as an arrhythmia. 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 SQTS?

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

What causes SQTS?

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

How is SQTS 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 SQTS

How is SQTS treated?

Treatment of SQTS 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 SQTS, to prevent triggering an arrhythmia.