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Fainting May Foretell Heart Troubles

by Dr. Audrey Sernyak

We've all seen videos posted on the Internet of people fainting on stage, in competitions or even during their own weddings.

Six in 10 of us will faint at some point in our lives. While fainting once is usually nothing to worry about, it is a good idea to see your doctor for a closer look. A brief loss of consciousness could be a sign of a serious heart problem.

"Fainting, or syncope, is caused by a sudden decrease in blood flow to the brain," said Lourdes interventional cardiologist Audrey Sernyak, MD, FACC. "After you lose consciousness and fall down, blood flow is restored, causing you to wake up."

Why We Faint

The first time someone faints, doctors can't always tell why. Most are linked to a sudden drop in blood pressure to your brain. The most common causes are not dangerous. They include:

  • The vasovagal reflex, which causes the heart rate to slow and the blood vessels to widen. This makes it harder for blood to defy gravity and be pumped from the lower part of the body to the brain. This temporary decrease in blood flow causes the fainting episode. Situational stress, such getting a shot or seeing blood, hearing bad news (called swooning in Victorian times), pain, fear, coughing or holding your breath can trigger the reflex.
  • Orthostatic hypotension, a sudden drop in blood pressure when you change position, such as standing up too quickly after lying down.
  • Heart rhythm changes, too-fast or too-slow heartbeats caused by problems with the heart's electrical system.

Dehydration, exhaustion and reactions to medications are also reasons why people faint.

"In most cases, fainting does not indicate a serious health issue," said Dr. Sernyak. "However, syncope could be a signal of cardiovascular disease, so see a doctor for evaluation."

Signs of Hidden Trouble

For a new study in the Journal of the American College of Cardiology, more than 37,000 patients who had fainted for the first time were followed for an average of four-and-a-half years afterward.

Compared with a control group of people who had never fainted, they were:

  • 75 percent more likely to be hospitalized for a heart event
  • 35 percent more likely to have a stroke
  • Five times as likely to need a pacemaker or defibrillator

The results suggest that many fainting adults, especially younger ones, have undiagnosed heart conditions. Rather than a meaningless event, this brief loss of consciousness may be an early symptom of a severe underlying disease.

Visit Your Doctor

See your doctor if you experience an unexplained fainting spell. Don't take this lightly. According to Dr. Sernyak, make sure to tell him or her if you:

  • Faint often in a short period of time
  • Faint without warning
  • You have chest pain or feel short of breath
  • Fainted while exercising
  • Have a fast or irregular heartbeat
  • Faint while also experiencing numbness or tingling on one side of the body
  • Have a family history of frequent fainting, or of sudden cardiac death

The American Heart Association has more information about the causes and complications of fainting. Go to and search for syncope.

Originally published in Lourdes Health System - Health Talk Online.

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