Risk Factors & Causes of Syncope

Risk Factors for Cardiovascular Syncope 

The risk of cardiovascular syncope increases with age. Those at greatest risk are people who have any of the following conditions:

  • Coronary artery disease (clogged blood vessels to the heart)
  • Chest pain caused by angina (lower blood supply to the heart)
  • Prior heart attack (myocardial infarction)
  • Ventricular dysfunction (weakness in the heart's pumping chambers)
  • Cardiomyopathy (structural problems with the heart's muscles)
  • An abnormal electrocardiogram (a common test to check for abnormal heart rhythms)
  • Recurrent episodes of Fainting that come on suddenly and without warning
  • Fainting during exertional activity or exercise
  • Some congenital heart defects or syndromes (like William's syndrome)
  • Channellopathies (defects of the electrical system of the heart) like Long QT syndrome and Brugada Syndrome

Signs of Cardiovascular Syncope

Cardiovascular syncope usually is sudden. There may be no warning signs that an individual is about to faint. Some people do feel the following:

  • Shortness of breath
  • Heart palpitations (feeling like your heart is racing, pounding, or fluttering)
  • Pain, pressure, tightness, or discomfort in the chest

Cardiovascular Syncope and Long QT Syndrome

Fainting is the primary symptom - and may be the only warning sign - of Long QT Syndrome (LQTS), an inherited electrical disorder of the heart. LQTS is believed to be a common cause of sudden and unexplained death in children and young adults. It may occur in as many as 1 in 2,000 individuals and causes up to 4,000 deaths in children and young adults each year in the United States.