Ventricular Fibrillation: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Ventricular Fibrillation?
Ventricular fibrillation is a heart emergency, so paramedics and emergency room doctors treat it first. A cardiologist, a doctor who treats heart problems, then looks for the cause and plans long-term care. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is ventricular fibrillation?
Ventricular fibrillation, or VF, is a severely abnormal heart rhythm. A heart rhythm problem is called an arrhythmia. VF is life threatening.
Fibrillation is an uncontrolled twitching or quivering of muscle fibers. In VF, this happens in the lower chambers of the heart. During VF, blood is not pumped from the heart. The heart normally pumps blood to the lungs, brain, and other organs. Even a few seconds without a heartbeat can lead to fainting or cardiac arrest.
Symptoms
A person who has VF suddenly collapses and becomes unconscious. This happens because the brain and muscles are not receiving blood from the heart.
Some people have warning signs within minutes to 1 hour before the collapse. These can include:
- Chest pain.
- Dizziness.
- Nausea.
- Palpitations, which are a rapid or irregular heartbeat you can feel.
- Shortness of breath.
Causes and who gets it
The most common cause of VF is a heart attack. VF can happen whenever the heart muscle does not get enough oxygen. Conditions that can lead to VF include:
- Electrocution accidents or injury to the heart.
- Heart attack or angina, which is chest discomfort.
- Heart disease that is present at birth.
- Heart muscle disease, in which the muscle becomes weak and stretched or thick.
- Heart surgery.
- A sudden blow to the chest right over the heart, called commotio cordis, most often in athletes.
- Some medicines.
- Very high or very low potassium levels in the blood.
Many people with VF have no history of heart disease. They often have risk factors, such as smoking, high blood pressure, and diabetes. Less often, inherited problems with the heart's electrical channels play a part.
How doctors diagnose it
A cardiac monitor, which shows the heart's rhythm, will show a very disorganized or chaotic rhythm in VF. After the emergency, doctors run tests to look for the cause of the VF.
Treatment
VF is a medical emergency. It must be treated right away to save a person's life. The most effective steps are strong chest compressions (part of CPR) and an early electric shock to the heart.
If a person collapses or becomes unconscious, call 911. While you wait for help, start CPR by pushing hard and fast in the center of the chest. Keep going until the person becomes alert or help arrives.
VF is treated with a quick electric shock through the chest from a device called an external defibrillator. The shock can restore a normal heartbeat right away. It should be given as quickly as possible. Many public places now have these machines. The chance of a successful rescue falls by 7% to 10% each minute after the collapse.
Medicines may be given to control the heartbeat and heart function. People at risk of VF may get an implantable cardioverter defibrillator, or ICD. This device is placed in the chest wall. It detects the dangerous heart rhythm and quickly sends a shock to correct it.
When to see a doctor
Call 911 or the local emergency number if a person collapses or becomes unconscious. Start CPR while you wait for help.
Call 911 or go to the emergency room if you have chest pain or discomfort lasting two minutes or more, trouble breathing, fainting, or a rapid, irregular pulse.
Family members and friends of people who have had VF and heart disease should take a CPR course. Courses are offered through the American Red Cross, hospitals, and the American Heart Association.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This kind of doctor can review risk factors such as smoking, high blood pressure, and diabetes. They can also help with follow-up after an emergency and coordinate care with a cardiologist. They cannot treat VF during an emergency.
Common questions
How is ventricular fibrillation treated?
VF is treated with a quick electric shock through the chest from a device called an external defibrillator. CPR is started while people wait for help. Medicines may be given to control the heartbeat, and some people at risk get an ICD.
Can a person survive ventricular fibrillation?
Yes, but only with quick treatment. VF leads to death within a few minutes unless it is treated quickly and properly. Long-term survival is low for people who live through an attack outside a hospital. People who survive may be in a coma or have long-term brain or other organ damage.
Is ventricular fibrillation the same as ventricular tachycardia?
No. Both start in the lower chambers of the heart, but they are different rhythms. In VF, the muscle quivers and blood is not pumped from the heart. Ventricular tachycardia is a pulse of more than 100 beats per minute from a ventricle, and it can also be deadly.
What does an ICD do?
An ICD, or implantable cardioverter defibrillator, detects a dangerous heart rhythm and quickly sends a shock to correct it. It can be placed in the chest wall of people who are at risk for VF.
Sources
- MedlinePlus - Ventricular fibrillation
- National Library of Medicine (PubMed Central) - Handling of Ventricular Fibrillation in the Emergency Setting
- MedlinePlus - Ventricular tachycardia
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
