Loss of consciousness or fainting is the most common sign of ventricular fibrillation.

Early ventricular fibrillation symptoms

It's possible that you may have other signs and symptoms that start about an hour before your heart goes into ventricular fibrillation and you faint. These include:

  • Chest pain
  • Rapid heartbeat (tachycardia)
  • Dizziness
  • Nausea
  • Shortness of breath

When to see a doctor

If you or someone else is having signs and symptoms of ventricular fibrillation, seek emergency medical help immediately. Follow these steps:

  • Call 911 or the emergency number in your area.
  • Begin cardiopulmonary resuscitation (CPR) to help maintain blood flow to the organs until an electrical shock (defibrillation) can be given. Push hard and fast on the person's chest — about 100 compressions a minute. It's not necessary to check the person's airway or deliver rescue breaths unless you've been trained in CPR. If you are trained, check the airway and then deliver rescue breaths after every 30 compressions.

Portable automated external defibrillators (AEDs), which can deliver an electric shock that may restart heartbeats, are available in an increasing number of places, such as in airplanes, police cars and shopping malls. They can even be purchased for your home. Portable defibrillators come with built-in instructions for their use. They're programmed to allow a shock only when appropriate.

Nov. 01, 2011