Ventricular fibrillation is always diagnosed in an emergency situation. Your doctors will know if you're in ventricular fibrillation based on results from:

  • Heart monitoring. A heart monitor that will read the electrical impulses that make your heart beat will show that your heart is beating erratically or not at all.
  • Pulse check. In ventricular fibrillation, there will be no pulse.

Tests to diagnose the cause of ventricular fibrillation

To find out what caused your ventricular fibrillation, you'll have additional tests, which can include:

  • Electrocardiogram (ECG). This test records the electrical activity of your heart via electrodes attached to your skin. Impulses are recorded as waves displayed on a monitor or printed on paper. Because injured heart muscle doesn't conduct electrical impulses normally, the ECG may show that a heart attack has occurred or is in progress.
  • Blood tests. Emergency room doctors take samples of your blood to test for the presence of certain heart enzymes that leak into your blood if your heart has been damaged by a heart attack.
  • Chest X-ray. An X-ray image of your chest allows your doctor to check the size and shape of your heart and its blood vessels.
  • Echocardiogram. This test uses sound waves to produce an image of your heart. During an echocardiogram, sound waves are directed at your heart from a transducer, a wandlike device, held on your chest. Processed electronically, the sound waves provide video images of your heart.
  • Coronary catheterization (angiogram). To determine if your coronary arteries are narrowed or blocked, a liquid dye is injected through a long, thin tube (catheter) that's fed through an artery, usually in your leg, to the arteries in your heart. The dye makes your arteries become visible on X-ray, revealing areas of blockage.
  • Cardiac computerized tomography (CT). In a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest.
  • Magnetic resonance imaging (MRI). For a cardiac MRI, you lie on a table inside a long tubelike machine that produces a magnetic field that aligns atomic particles in some of your cells. Radio waves aimed at these aligned particles produce signals that create images of your heart.


Emergency treatments for ventricular fibrillation focus on restoring blood flow through your body as quickly as possible to prevent damage to your brain and other organs. After blood flow is restored through your heart, if necessary, you'll have treatment options to help prevent future episodes of ventricular fibrillation.

Emergency treatments

  • Cardiopulmonary resuscitation (CPR). This treatment can help maintain blood flow through the body by mimicking the pumping motion your heart makes. CPR can be performed by anyone, including family members.

    In a medical emergency, first call for emergency medical help, then start CPR by pushing hard and fast on the person's chest — about 100 to 120 compressions a minute. Allow the chest to rise completely between compressions.

    Unless you're trained in CPR, don't worry about breathing into the person's mouth. Keep up chest compressions until a portable defibrillator is available or emergency personnel arrive.

  • Defibrillation. The delivery of an electrical shock through the chest wall to the heart momentarily stops the heart and the chaotic rhythm. This often allows the normal heart rhythm to resume.

    If a public-use automated external defibrillator (AED) is available, anyone can administer it. Most public-use AEDs voice instructions as you use them. Public-use AEDs are programmed to recognize ventricular fibrillation and send a shock only when needed.

Treatments to prevent future episodes

If your doctor finds that your ventricular fibrillation is caused by a change in the structure of your heart, such as scarred tissue from a heart attack, he or she may recommend that you take medications or have a medical procedure performed to reduce your risk of future ventricular fibrillation and cardiac arrest. Treatment options can include:

  • Medications. Doctors use various anti-arrhythmic drugs for emergency or long-term treatment of ventricular fibrillation. A class of medications called beta blockers is commonly used in people at risk of ventricular fibrillation or sudden cardiac arrest.

  • Implantable cardioverter-defibrillator (ICD). After your condition stabilizes, your doctor is likely to recommend implantation of an ICD. An ICD is a battery-powered unit that's implanted near your left collarbone. One or more flexible, insulated wires (leads) from the ICD run through veins to your heart.

    The ICD constantly monitors your heart rhythm. If it detects a rhythm that's too slow, it sends an electrical signal that paces your heart as a pacemaker would. If it detects ventricular tachycardia or ventricular fibrillation, it sends out low- or high-energy shocks to reset your heart to a normal rhythm. An ICD is more effective than drugs for preventing arrhythmia-induced cardiac arrest.

  • Coronary angioplasty and stent placement. This procedure is for the treatment of severe coronary artery disease. It opens blocked coronary arteries, letting blood flow more freely to your heart. If your ventricular fibrillation was caused by a heart attack, this procedure may reduce your risk of future episodes of ventricular fibrillation.

    Doctors insert a long, thin tube (catheter) that's passed through an artery, either in your leg or arm, to a blocked artery in your heart. This catheter is equipped with a special balloon tip that briefly inflates to open up a blocked coronary artery. At the same time, a metal mesh stent may be inserted into the artery to keep it open long term, restoring blood flow to your heart.

    Coronary angioplasty may be done at the same time as a coronary catheterization (angiogram), a procedure that doctors do first to locate narrowed arteries to the heart.

  • Coronary bypass surgery. Another procedure to improve blood flow is coronary bypass surgery. Bypass surgery involves sewing veins or arteries in place at a site beyond a blocked or narrowed coronary artery (bypassing the narrowed section), restoring blood flow to your heart. This may improve the blood supply to your heart and reduce your risk of ventricular fibrillation.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Lifestyle and home remedies

Lifestyle changes that help keep your heart as healthy as possible include:

  • Eat a healthy diet. Heart-healthy foods include fruits, vegetables and whole grains, as well as lean protein sources such as soy, beans, nuts, fish, skinless poultry and low-fat dairy products. Avoid extra salt (sodium), added sugars and solid fats.

  • Exercise regularly. Aim for 150 minutes a week of moderate aerobic activity, 75 minutes a week of vigorous aerobic activity, or a combination of moderate and vigorous activity.

  • Stop smoking. You're more likely to quit successfully if you take advantage of strategies proved to help. Talk with your doctor about medications that can reduce your cravings and reduce symptoms of nicotine withdrawal.

    Your doctor also can recommend telephone counseling and online tools — such as free services offered by the American Cancer Society — that provide critical emotional support.

  • Keep your blood pressure and cholesterol levels in a healthy range. Take medications as prescribed to correct high blood pressure (hypertension) or high cholesterol, and maintain a healthy body weight.

  • Limit alcohol intake. Too much alcohol can damage your heart. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.

  • Maintain follow-up care. Take your medications as prescribed and have regular follow-up appointments with your doctor. Tell your doctor if your symptoms worsen.

Coping and support

Living with ventricular arrhythmia can cause a range of difficult feelings, including fear, anger, guilt and depression. Prioritize your emotional well-being to prevent anger- and stress-related heart rhythm problems.

Some types of complementary and alternative therapies may help reduce stress, such as:

  • Yoga
  • Meditation
  • Relaxation techniques

Getting support from your loved ones also is key to managing stress. Because arrhythmias don't cause obvious symptoms, your friends and family may overlook your condition at times. Share your emotions and ask for help meeting your treatment goals.

Oct. 24, 2017
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