Complications

Proper medical treatment and lifestyle changes can help prevent complications related to long QT syndrome.

Complications of long QT syndrome include:

• Torsades de pointes ('twisting of the points'). This is a life-threatening form of ventricular arrhythmia. Your heart's two lower chambers (ventricles) beat fast and chaotically, making the waves on an ECG monitor look twisted. The heart pumps out less blood. The lack of blood to the brain causes you to faint suddenly and, often, without warning.

  If the episode lasts for a long time, fainting can be followed by a full-body seizure. If the dangerous rhythm does not correct itself, then a life-threatening arrhythmia called ventricular fibrillation follows.

• Ventricular fibrillation. This condition causes the ventricles to beat so fast that your heart quivers and stops pumping blood. Unless your heart is shocked back into a normal rhythm by a defibrillator, ventricular fibrillation can lead to brain damage and sudden death.
• Sudden death. It's now known that long QT syndrome might explain some cases of sudden death in young people who otherwise appear healthy.
• Unexplained fainting, drownings, seizures or other accident. Long QT syndrome might be responsible for some otherwise unexplained deaths in children and young adults.