Disclaimer: This material should be used to supplement your understanding of the cardiovascular system. Any use of the information given in this post series is at your own risk and should be verified prior to making it a part of your nursing practice. There may be affiliate links associated with some products but we promise that we will never recommend anything that we don’t use ourselves.

What do black mamba snakes, saltwater crocodiles, and Ventricular Fibrillation all have in common?

They can all kill you…Quickly.



Because that is terrifying, you should know a great deal about this arrhythmia. The most concerning fact about V-Fib is the heart can only sustain this arrhythmia for 6 minutes before cardiac arrest and death occur…

I want you to think about what you can do in 6 minutes.

I could go on, but my point is that 6 minutes is not a lot of time. During that six minutes, you do not want to forget what you should do. Your patient appreciates if you are on top of your game and keep them safe.



So, in the spirit of safety and all those who are alive, let’s dive into the Great White Shark of Arrhythmias.

Ventricular Fibrillation (AKA Vfib or VF) is a life-threatening arrhythmia with disorganized chaotic electrical activity coming from the ventricles that cause the ventricles to quiver. The main cause of this chaos is a lack of blood flow to the heart. So think about what can cause a lack of blood flow to the heart? Some of the major reasons are:

  • Heart attack
    • The literal definition is decreased blood flow to the heart causing death to the cardiac muscle tissues, so yeah, it can cause VFib.
  • Cardiomyopathy
    • The cardiac muscles become hardened/thickened/ridged and scar tissue ensues, causing decreased ability to pump correctly, which decreases blood flow to the heart.
  • Sepsis
    • Septic shock leads the body to a major decrease in blood pressure and adequate blood flow to the body and the heart
  • Coronary Artery Disease (CAD)
    • The blood vessels that give blood supply to the heart become clogged up and no longer deliver blood to the heart adequately.
  • Ventricular Tachycardia
    • This arrhythmia causes the ventricles to not pump properly, thus the heart is receiving less blood flow.

The lack of blood flow to the heart cells causes them to spasm/quiver and the heart is no longer pumping blood to the other parts of the heart. When the ventricles are quivering, they are not pumping any blood to the rest of the body. Which, as you can imagine, is problematic, and why death ensues so quickly.

Because there are so many things that can cause VFib, I am not going to sweat remembering them all and you shouldn’t either. Instead, you should be thinking about the outcomes of your patient’s situation and be aware of the signs and symptoms of VFib. So if you have a patient who is complaining of chest pain, be mindful that one of the scary causes of chest pain is decreased blood flow to the heart. It will then lead you to what happens when the blood flow to the heart slows down, which is eventually VFib.

Signs and symptoms of Ventricular Fibrillation (V-Fib)

Because the body is not circulating blood, the person will not be conscious, so the biggest sign of Ventricular Fibrillation is loss of consciousness. The next obvious sign of VFib is that the patient will not have a pulse. Before the patient goes into ventricular fibrillation, they will likely have the same signs and symptoms of a heart attack: Chest pain, shortness of breath, numbness in the arms or legs, etc.

After you think your patient might be in VFib, you should get an EKG/ECG to confirm, and also get the crash cart and place the patient on the defibrillator. To confirm VFib, you will need to know what it even looks like, so…

What does Ventricular Fibrillation (V-Fib) look like?


Note: There aren’t any P, Q, R, S, or T waves, just pure chaos of varying shapes and sizes.

This rhythm is the easiest, in my opinion, to recognize. You don’t have to measure anything, because there isn’t anything to measure. If you struggle with recognizing ECG/EKG arrhythmia’s I recommend you carry this pocket guide around with you!

In Ventricular Fibrillation, the heart rate can be anywhere from 150 beats per minute to 500 beats per minute… yup, you read that right.

So how does this translate from the EKG/ECG to the what the heart is doing?

Well, myocytes are normally homogeneous in behavior. However, stress, injury, or any type of damage to one cell, or even a group of cells, causes them to behave differently. If the electrical current running through the cells gets all jumbled it can cause re-entry of electrical current.

The EKG/ECG that you see in VFib is a bunch of electrical circuits re-entering the heart at various points causing multiple contractions.



FYI:  You can also shock a patient INTO Ventricular Fibrillation when they were not in Vfib to begin with. This occurs if you send a shock right at the beginning of the T-wave. That is why it is vital to synchronize the defibrillator to the R wave when cardioverting. A patient may have synchronized cardioversion if they are in Supraventricular Tachycardia, Ventricular Tachycardia, unstable Atrial Fibrillation, Atrial Flutter, or any other atrial tachycardia. So knowing how to use the defibrillator is pretty stinking important.

Nursing interventions/Considerations for Ventricular Fibrillation (V-Fib)

In V-Tach you needed to check a pulse first, but in Vfib, you jump on the chest and start CPR while shouting for help. The most important thing is to get the defibrillator on the patient ASAP and deliver the shock. The shock will be what gets them out of Vfib and the chest compressions are what will help sustain them long enough until you can deliver the shock.

Remember: Ventricular Fibrillation is a true emergency and you need to act quickly.

Something to note is that the EKG/ECG becomes smaller/finer the longer Vfib persists, leading to flat line. Thus if someone is in Vfib with tiny little waves, you need to act super quick because your time is almost up.

Treatment: Meds/Tests/Imaging for Ventricular Fibrillation (V-Fib)

Each facilities code protocols are different, so know your facilities protocols, particularly if you are a travel nurse! In general, however, you will follow the BLS and/or ACLS algorithms. So, you are going check for a pulse while simultaneously calling for help. There won’t be a pulse if they are in VFib so you will start chest compressions while help arrives. Next, defibrillator pads will be placed on the patient. Complete a rhythm check as quickly as possible, which will enable you to deliver a shock earlier and increase the patient’s chance of survival.

Initially, Automatic External Defibrillators (AEDs) and defibrillators confused me. To clarify,  a simple AED will just tell you if the rhythm is shockable or not with one big button that says “Shock” for you to push. This is what we train on for our BLS certification and they can be found in the general public.

Unlike in the general public, in the hospital, you will have a defibrillator that can either defibrillate, cardiovert, or pace.  Depending on where you work and what your certifications are, you may have a defibrillator that can only function like an AED. If you work with critical care patients, you will be Advanced Cardiac Life Support (ACLS) certified. This will require you to know how to switch between defibrillation, cardioversion and pacing modes.

  • Defibrillation is when you deliver a shock in life-threatening arrhythmias, it is delivered whenever the AED is charged rather than on a specific wave or at a specific time.
  • Cardioversion is when you deliver a shock at a specific time or on a specific wave to convert the patient out of the non-life-threatening arrhythmia they are in.
  • Pacing mode is used when a patient is super bradycardic and needs multiple shocks delivered continuously on the R-wave to keep the heart rate high enough to sustain life.

Another difference between BLS and ACLS providers is the ability to choose the amount of Joules delivered in each shock. BLS providers use the AED and the shock delivered is the standard amount of Joules for that brand of AED. ACLS providers can choose the amount of Joules to deliver in a shock. Usually, you start between 120J and 200J but depending on the person’s size and the situation. Defibrillators are capable of delivering up to 360J. It can be harmful to deliver too small of an amount of Joules so when in doubt deliver a higher amount.

The goal of treatment is to bring the patient back to a rhythm that is compatible with life.

If the cause of the VFib is unable to be reversed then an Implantable Cardioverter Defibrillator (ICD) is an option, especially if the patient is able to be sustained long enough to have one surgically implanted.

Extended care for patients with Ventricular Fibrillation (VFib)

Patients who survive VFib, need to be discharged with education on when to call 911, how to perform CPR (especially the family members), and a clear plan on their medications as well as check up appointments. You should urge the patient strongly to change any behaviors that may have contributed to VFib. Such as quitting smoking or dietary changes.


Written by: ME! Susan DuPont of BossRN.com who is a full-time nurse in a level I trauma Emergency Room. In her spare time, she loves the outdoors, fishing, and hunting.

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