What is V-Fib? Understanding A Potentially Deadly Heart Rhythm

Ventricular fibrillation, commonly known as V-Fib, is a life-threatening type of arrhythmia, or abnormal heart rhythm. During V-Fib, the heart’s lower chambers (ventricles) quiver uselessly instead of pumping blood. If not properly treated, it can lead to cardiac arrest and death within minutes. Let’s dive deeper into the causes, symptoms and treatment of V-Fib during a medical emergency.



In many cases, the exact trigger for V-Fib is unknown. It often occurs without warning in people with seemingly healthy hearts. What we do know about ventricular fibrillation is that certain conditions put extra stress on the heart muscle. This type of stress can, in turn, disrupt the heart’s electrical signals and trigger V-Fib. Such conditions are:

  • Heart attack or coronary artery disease
  • Thickened or enlarged heart muscle (cardiomyopathy)
  • Congenital heart defects
  • Electrolyte imbalances like low potassium or magnesium
  • Severe hypothermia or frostbite
  • Drug overdoses or toxic exposures




We can’t see V-Fib causes externally but we can definitely point to symptoms of V-Fib to look for that commonly occur, even before someone suddenly collapses, falls unconscious or has no pulse.

For example, watch for these warning signs in which the individual may first experience:

  • Dizziness or light-headedness
  • Racing heartbeat (palpitations)
  • Chest pain
  • Shortness of breath



What’s The Difference Between V-Fib and A-Fib?

Great question. The two are very different and it’s easy to get them confused. So let’s be clear on the state of emergency in each.

V-Fib is a life-threatening condition.
Make no mistake that V-Fib a medical emergency that requires attention immediately. During V-Fib, the ventricles are contracting in a rapid, unsynchronized way that results in little or no blood being pumped from the heart. The heart stops circulating blood effectively and if not treated promptly, cardiac arrest will be the likely result. One cannot “live with V-Fib.”

A-Fib is an irregular heart rate that increases the risk of heart disease. 
Atrial Fibrillation, or A-Fib, is an abnormal heart condition that occurs in the upper chambers of the heart, in which an often rapid heart rate causes poor blood flow into the ventricles. The atria will quiver rather than beat effectively, which can increase the risk of blood clots, stroke and heart failure. You may be able to “live with” A-Fib but it will always carry this medical risk if left untreated.

A-Fib tends to receive more public visibility than V-Fib due to the number of celebrities and athletes who have been diagnosed with A-Fib and chosen to receive heart valve surgery. Some of the more famous names on this list include Mick Jagger, Sharon Stone, Arnold Schwarzenegger, Dustin Hoffman, journalist Bob Woodward and Camilla, Duchess of Cornwall.


Treatment for V-Fib with AEDs and CPR

How do you best treat ventricular fibrillation after someone has collapsed? As the medical emergency that it is with the use of an electrical shock to stop the erratic rhythms and restore a normal heartbeat. This is best delivered with an automated external defibrillator (AED) device, like any of the variety of AEDs you’ll find here at AED.US.

We can’t say it enough: Calling 9-1-1 is important, but simply waiting for EMS to arrive may be too late. The chain of survival depends on your use of an AED now.

With this in mind, know where your AED on site is located and call someone nearby for help in retrieving the device.

By the way, if you don’t know where your AED is offhand, now is the time to find it. There will be no time when a real medical emergency occurs to leave this to chance. If it seems like there isn’t enough time for someone to properly retrieve an AED and run back to the victim within a few minutes, check out our blog post on how to calculate the precise number of AEDs you need for your facility.

The AED will guide you through the process of checking for unconsciousness and shocking the heart if V-Fib is detected. Quick CPR and defibrillation within 3-5 minutes provide the best chance of resuscitating someone in V-Fib cardiac arrest.

At the hospital, doctors may prescribe medications, catheterization procedures or surgery to prevent future episodes. Some high-risk patients receive an implantable cardioverter defibrillator (ICD) to automatically detect and stop V-Fib rhythms.

While V-Fib is often unexpected, being prepared with AED/CPR training and calling emergency services quickly can make the difference between life and death.

Don’t delay – V-Fib is a “shock required” situation and the best way to be ready to act is to get equipped with the AED technology and CPR training direct from AED.US today. Talk to one of our experts standing by at 888-652-1882.