Ventricular fibrillation (V-fib) is a type of arrhythmia, or irregular heartbeat that affects your heart’s ventricles. Your heart is a muscle system that contains four chambers; the two bottom chambers are the ventricles. In a healthy heart, your blood pumps evenly in and out of these chambers, and this keeps blood flowing throughout your body.
An arrhythmia that starts in your ventricle is called ventricular fibrillation. This occurs when the electrical signals that tell your heart muscle to pump cause your ventricles to quiver instead. The quivering means that your blood is not pumping blood throughout your body. In some people, V-fib may happen several times a day. This is called an “electrical storm.”
Because V-fib can lead to cardiac arrest and death, it requires immediate medical attention.
A defibrillator is an electronic device used to treat V-fib. It produces an electric shock that can restore a normal heartbeat. Many public places, such as malls, movie theaters, and restaurants, now have defibrillators on-site. CPR training often includes instruction on their use. If you find and use a defibrillator promptly when someone collapses, you can save a life.
Symptoms of V-fib include:
Loss of responsiveness
Inability to breathe
Anyone can develop V-fib, but the most common risk factors are:
A weakened heart muscle from an infection or illness
A heart attack
Recovery from a recent heart attack
A heart condition called long QT syndrome, which increases your risk for a specific type of V-fib called torsades
Certain medications that affect heart function
To diagnose V-fib, your physician will consider:
Your vital signs, such as your blood pressure
Tests of heart function, such as an electrocardiogram
Your overall health and medical history
A description of your symptoms that you, a loved one, or a bystander provides
A physical examination
There are two stages of treatment for V-fib. The first stops your V-fib and saves your life. The second reduces your chances of developing V-fib in the future. Treatment includes:
CPR. The first response to V-fib may be CPR (cardiopulmonary resuscitation). This will keep your blood moving.
Defibrillation. You will need this during or immediately after the V-fib. Electric shock will correct the signals that are telling your heart muscles to quiver instead of pump.
Medication. Your doctor may give you drugs immediately after V-fib to help you control and prevent another episode. He or she may prescribe additional medications to control arrhythmia and reduce your risk over time.
Catheter ablation. This procedure uses energy to destroy small areas of your heart affected by the irregular heartbeat.
Left cardiac sympathetic denervation. This is a surgical procedure that might help people with frequent V-fib events, although it is not yet commonly used.
Complications are problems that your condition can cause. With V-fib, complications include the possibility of a repeat episode and cardiac arrest. V-fib can be fatal.
You can help prevent V-fib by taking any medications that your doctor has prescribed to manage your arrhythmia. Follow your doctor's instructions exactly. If you are at high risk for V-fib, your doctor can implant a tiny defibrillator in your body. Talk with your doctor about whether this is an appropriate option for you.
If you are at risk for V-fib, you should wear a medical ID and let friends and loved ones know what to do in an emergency. Talk with them about when to call 911, and encourage them to learn how to use a defibrillator.
It is extremely important to make sure that people around you know what to do in an emergency. Someone should call 911 immediately if you experience any of the following symptoms of V-fib:
Loss of consciousness
People who have had V-fib, or who are at high risk for it, should follow their doctors’ recommendations for taking medication to control arrhythmia. It's also helpful to research and discuss other more invasive options, such as an implantable defibrillator, or surgery, to prevent V-fib. Educate your friends and family about how to respond if you collapse and stop breathing.