Ventricular Fibrillation: Symptoms & First Aid Treatment

Picture of Ventricular fibrillation patient


Ventricular fibrillation (V-fib or VF) is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly. Ventricular fibrillation is the most commonly identified arrhythmia in cardiac arrest patients.

Which is more dangerous to the heart atrial or ventricular fibrillation?

Ventricular fibrillation is more serious because the ventricles have major responsibility for pumping blood from the heart to the lungs and all other organs of the body.

What is the difference between atrial fibrillation and ventricular fibrillation?

The two lower chambers are the left ventricle and the right ventricle. When the two upper chambers – the atria – contract at an excessively high rate, and in an irregular way, the patient has atrial fibrillation. When the two lower chambers beat irregularly and flutter, the patient hasventricular fibrillation.

What is the meaning of ventricular arrhythmias?

Ventricular arrhythmias are abnormal heart rhythms that originate in the bottom chambers of the heart called the ventricles. These rhythms can occur as a result of damage to the heart muscle from a heart attack or cardiomyopathy – or can occur in patients with hearts that seem structurally normal.

Symptoms of Ventricular fibrillation

Loss of consciousness is the most common sign of ventricular fibrillation.

Early signs and symptoms

A condition in which the lower chambers of your heart beat too fast (ventricular tachycardia) can lead to ventricular fibrillation. Signs and symptoms of ventricular tachycardia include:

  • Chest pain
  • Rapid heartbeat (tachycardia)
  • Dizziness
  • Nausea
  • Shortness of breath
  • Loss of consciousness

Causes of Ventricular fibrillation

The heart pumps blood to the lungs, brain, and other organs. If the heartbeat is interrupted, even for a few seconds, it can lead to fainting (syncope) or cardiac arrest.

Fibrillation is an uncontrolled twitching or quivering of muscle fibers (fibrils). When it occurs in the lower chambers of the heart, it is called ventricular fibrillation. During ventricular fibrillation, blood is not pumped from the heart. Sudden cardiac death results.

The most common cause of VF is a heart attack. However, VF can occur whenever the heart muscle does not get enough oxygen for any reason. Conditions that can lead to VF include:

  • Electrocution accidents or injury to the heart
  • Heart attack
  • Heart disease that is present at birth (congenital)
  • Heart muscle disease, including cardiomyopathies
  • Heart surgery
  • Narrowed coronary arteries
  • Sudden cardiac death (commotio cordis); most often occurs in athletes who have had an injury over the surface of the heart
  • Medications

Most people with VF have no history of heart disease. However, they often have heart disease risk factors, such as smoking, high blood pressure, and diabetes.

Treatment for Ventricular fibrillation

Ventricular fibrillation must be treated as an extreme emergency. Cardiopulmonary resuscitation (CPR: see Cardiac Arrest : First-Aid Treatment) must be started as soon as possible within a few minutes. It must be followed by defibrillation (an electrical shock delivered to the chest), as soon as the defibrillator is available. Antiarrhythmic drugs may then be given to help maintain the normal heart rhythm.

When ventricular fibrillation occurs within a few hours of a heart attack in people who are not in shock and who do not have heart failure, prompt cardioversion restores normal rhythm in 95% of people, and the prognosis is good. Shock and heart failure suggest severe damage to the ventricles. If they are present, even prompt cardioversion has only a 30% success rate, and 70% of people who are resuscitated die without regaining normal function.

People who are successfully resuscitated from ventricular fibrillation and survive are at high risk of another episode. If ventricular fibrillation is caused by a reversible disorder, that disorder is treated. Otherwise, most people have an implantable cardioverter-defibrillator (ICD: see Abnormal Heart Rhythms:Restoring normal rhythm) surgically implanted to correct the problem, if it recurs, by delivering a shock. Such people are often also given drugs to prevent recurrences.