Ventricular fibrillation (VF) or V-fib is a dangerous condition in which your heart beats in an abnormal rhythm. Your heart should beat in a regular, steady pattern. VF causes your heart to beat quickly and out of rhythm.

VF is considered to be the most serious type of abnormal heart rhythm. It is an emergency condition that may be brought on by a heart attack.

When VF occurs, the two chambers in the lower portion of your heart aren’t able to pump hard enough to move blood through your body. These lower chambers are called ventricles. This makes your blood pressure drop quickly and keeps blood from traveling through your body. As a result, blood can’t get to your vital organs. VF can be preceded by another arrhythmia called ventricular tachycardia (VT).

Fainting or losing consciousness are the most common symptoms of VF. Earlier symptoms include:

These early symptoms can occur 1 hour or less before fainting or loss of consciousness occurs.

Is this an emergency?

If you’re experiencing VF symptoms, have someone nearby call emergency services. If someone near you appears to be experiencing a heart attack, stay with them after you call for help.

If they lose consciousness and stop breathing, you will need to perform CPR:

  • Lay the person on their back, and clear their airways.
  • Place one hand over the other on their sternum.
  • Press quickly, 2 compressions per second.
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Getting a person to a hospital when VF occurs is vital. Death can occur within seconds after the condition starts. Other complications can include coma, loss of nerve function, and changes in neurological (mental) function due to a temporary loss or reduction of oxygen to the brain.

Experiencing VF for a long time can also lead to kidney and liver problems. You may also be at risk of getting another VF episode or other heart problems in the future.

While the exact cause of VF isn’t always known, the problem typically stems from interruptions in the electrical impulses that control your heartbeat. A heart attack or loss of blood flow to your heart can set off VF.

Several things can cause or raise your risk of ventricular fibrillation:

  • Some medications and severe illnesses can also cause VF.
  • Leading a mainly sedentary life or not getting enough exercise may raise the risk of having VF.
  • Electrolyte imbalances, such as low potassium or high potassium, are linked to VF.
  • Acidosis can change the PH of your blood, making it highly acidic.
  • Cardiomyopathy is a disease that can weaken the muscle of your heart.
  • A history of heart conditions in your family raises your overall risk to develop them as well.
  • Alcoholism is also known to put stress on the heart.
  • Congenital channelopathies can cause VF and increase your risk of sudden cardiac death.

VF often begins with ventricular tachycardia, which is a rapid heartbeat that changes the electrical impulses in your heart. This most often occurs in people who have scar tissue from previous heart attacks or heart muscle damage due to heart conditions. If left untreated, ventricular tachycardia will likely lead to VF.

Your doctor can use testing to determine if you’re at risk of a VF episode. Examples of tests that are used for diagnosis include:

  • an electrocardiogram (ECG) to see how your heart is beating
  • blood pressure and pulse or heart rate monitors
  • blood test to check for electrolyte imbalances in the body
  • an X-ray to look at your heart
  • an echocardiogram, which uses sound waves to create an image of your heart in action
  • an electrophysiology study, in which electrodes are placed inside your heart to monitor its electrical functioning
  • Holter monitoring, in which electrodes are attached to your chest and connected to a small machine called a Holter monitor that keeps track of your heart rhythms for a period determined by your doctor (usually 24 hours)
  • a stress test, in which your heart is monitored while you exercise

Another test — called T-wave alternans — can also help diagnose the condition. In this type of test, slight changes in your electrocardiogram’s T wave are monitored during gentle exercise. A T wave is one of the heart waves depicted on the electrocardiogram, which is a graphic visual representation of your heart’s electrical activity. The T wave is known for its rapidly changing, unsteady behavior.

This testing can be beneficial in predicting risk. However, during a VF event, your doctor must make a quick diagnosis. This includes listening to your heart for the presence of a heartbeat. Your doctor can also use a cardiac monitor or EKG to view your heart rate and rhythm.

Similar conditions

Ventricular fibrillation is related to and has overlapping symptoms with a variety of other conditions:

How your VF is treated is always the same. Your medical team may employ any combination of these treatments but will always shock your heart back into normal rhythm. Additional treatments depend on the underlying cause:

  • CPR can help move blood through your body to vital organs during cardiac arrest. Proper training in CPR can save a loved one’s life during an emergency.
  • Automated external defibrillator (AED) delivers electrical impulses to your heart in the event of a heart attack. These portable devices are often available in public spaces.
  • Additional electrolytes to correct imbalances in the body that may be linked to VF.
  • Medications can minimize irregular heartbeats or keep your heart pumping harder.
  • Implantable cardioverter defibrillator (ICD) monitors your heart rhythms and sends out shocks when necessary to increase or decrease your heart rhythm. This is different from an implanted pacemaker, which constantly fires to maintain a regular rhythm.
  • Catheter ablation is a procedure that uses energy to remove small areas of the heart affected by the VF.
  • Cardiac catheterization with percutaneous coronary intervention involves the insertion of a thin tube into your heart to open the blocked artery. A cardiac stent, which is a mesh tube, may also be permanently placed in the artery to help it remain open.
  • Coronary bypass surgery involves the attachment of a healthy artery to your blocked one. This will allow blood to bypass the blocked artery and flow smoothly through the newly attached artery.
  • Left cardiac sympathetic denervation is a rare procedure that is used to slow down the left side of the heart in people who have uncontrolled VF due to a genetic cause.

In the future, you may wish to purchase an AED to keep at your home. Bystanders in your home could use this lifesaving device to restore your heart rhythm in the event of a VF episode.

CPR can help save a life

If someone you love is living with a heart condition, CPR training is an easy (and often free) way to help keep them safe. You may also want to purchase an AED to keep at their home.

The American Red Cross offers CPR training all over the United States, and they have some online classes now as well. Use their website to find the closest training near you.

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A healthy lifestyle and healthcare are vital to keeping your heart healthy and lowering your risk of VF. This means:

  • You should eat a heart-healthy diet.
  • You should stay active, such as by walking 30 minutes per day.
  • If you smoke, start thinking about ways to help you quit. Smoking can affect your arteries’ flexibility and overall cell health. Taking steps to quit can make a dramatic difference in your heart health.
  • Avoid drinking excess alcohol, which can put extra stress on your heart.
  • Let your family know about your condition, so they can help support you.
  • Maintaining a healthy weight, blood pressure, and cholesterol levels can also help to prevent cardiac issues, such as VF.
  • If you have a chronic health condition such as diabetes, thyroid condition or kidney disease, take treatment as prescribed by your doctor and go to your regular check-ups.
  • Keep a record of your family medical history (if possible) and let your doctor know if you have genetic heart issues.

Ventricular fibrillation (VF) is a serious form of heart arrhythmia. There are several reasons you may have VF and the cause may not always be known or controllable.

If you have symptoms of VF, it’s critical to get urgent help. If you have been diagnosed with VF, let your family and friends know. Wearing a health bracelet that says you have VF can be lifesaving if you experience VF again.