Ventricular Fibrillation | Symptoms and Treatment| MedStar Health

A dangerously fast heartbeat that requires emergency care

Ventricular fibrillation, also known as VFib, is a serious type of heart rhythm disorder that involves the heart quivering or twitching. The heart can’t pump blood to the rest of the body, which leads to sudden cardiac arrest .

Without lifesaving care, ventricular fibrillation can be fatal. The physicians in our Cardiac Electrophysiology Program  are highly trained advanced subspecialists who manage even the most complex arrhythmias.

The most common cause of ventricular fibrillation is a lack of blood flow to the heart or damage after a heart attack . Another type of fast heartbeat called ventricular tachycardia  can also cause this condition.

If you or someone else is having these symptoms, call 911 right away.

What are the symptoms of ventricular fibrillation?

The most common symptoms are loss of consciousness and trouble breathing. A person with ventricular fibrillation may not be breathing at all or may only be able to gasp for air. Chest pain, dizziness and nausea are other possible signs of this condition.


Emergency tests of your heartbeat and pulse will help first responders and doctors diagnose and treat you. You also may need an electrocardiogram or other tests to determine what caused your condition.


An echocardiogram uses high-frequency sound waves to create images of your heart.

Electrocardiogram (ECG)

An electrocardiogram, also known as an ECG, measures the heart’s electrical activity.

Electrophysiology testing

Electrophysiology testing is used to evaluate the cause and location of an abnormal heartbeat (known as an arrhythmia).

Event monitors

An event monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but where an electrocardiogram takes place over a few minutes, an event monitor measures heart rhythms over a much longer time.

Holter monitors

A Holter monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but whereas an electrocardiogram records over a few minutes, a Holter monitor records over the course of a day or two.

Loop recorder

A loop recorder is a device that’s implanted underneath the skin of your chest to record your heart rhythm for up to three years.


Emergency, lifesaving treatment for ventricular fibrillation includes CPR and defibrillation. Medications can reduce your risk for the condition in the future, as can an implantable cardioverter-defibrillator (ICD) or catheter ablation.

Arrhythmia treatments (heart rhythm)

Treatments for arrhythmias, or heart rhythm disorders, such as minimally invasive procedures, implantable devices and surgery, vary based on the type and severity of your condition.

Cardiac ablation

Cardiac ablation uses heat or cold to destroy heart tissue causing abnormal heart rhythms known as arrhythmias.

Implantable cardioverter defibrillator (ICD)

An implantable cardioverter defibrillator (ICD) is a device implanted below your collarbone that monitors your heart’s rhythm. When it detects an abnormal rhythm, it delivers an electrical impulse or shock to the heart to correct it.

Additional information

Electrophysiology program

We are leaders in developing and using the latest procedures and technologies to treat heart rhythm disorders, and our cardiac electrophysiology laboratory is one of the most sophisticated in North America.

Ask MedStar Heart & Vascular Institute

Have general questions for our heart and vascular program? Email us at If you have clinically-specific questions, please contact your physician’s office.