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• Back to Diseases and Conditions
• Arrhythmias
• Atrial Fibrillation
• Bradycardia or Low Heart Rate
• Brugada Syndrome
• Long QT Syndrome
  • Signs and Symptoms
  • Risk Factors
  • Causes
  • Diagnosis
  • Treatments
  • Physicians and Services
• Palpitations
• Sudden Death or Cardiac Arrest
• Syncope or Fainting
• Tachycardia or Fast Heart Rate
• Wolff-Parkinson-White Syndrome

Signs and Symptoms

You may not have any signs and symptoms of long QT syndrome. However, some people exhibit the following signs and symptoms:

Fainting (Syncope) Spells

The most common sign of long QT syndrome, these fainting spells are the result of your heart's beating temporarily in a chaotic fashion. This is likely to happen with physical exercise, intense emotion or when startled. It can happen without warning.

Seizures

Seizures may occur if the brain is deprived of oxygen as your heart continues to beat erratically.