The ventricles are the large lower chambers of the heart. They are responsible for moving blood to the organs and tissues of the body. In ventricular fibrillation, the heart’s ventricles contract in a rapid and chaotic manner. As a result, little or no blood is pumped from the heart. Unless emergency medical help is provided immediately, ventricular fibrillation will lead to cardiovascular collapse and sudden death.
Causes of ventricular fibrillation include:
Ventricular fibrillation is most commonly associated with CAD. Factors that can increase risk of CAD will also increase the risk of ventricular fibrillation. These include:
Ventricular fibrillation happens without warning. When it occurs, symptoms may include:
Ventricular fibrillation is suspected when a person collapses suddenly and has no detectable pulse or heartbeat. The diagnosis is confirmed by ECG. An ECG records the heart’s activity by measuring electrical currents through the heart muscle.
Ventricular fibrillation must be treated as an extreme emergency and treatment must be administered within 4-6 minutes.
CPR, which begins with giving chest compressions, is a temporary procedure that can help maintain some blood flow to the brain, heart, and other vital organs until trained medical personnel are available to provide more advanced treatment.
In defibrillation, an electronic device is used to give an electric shock to the heart. The electric shock helps to reestablish the normal contraction rhythms of the heart. An automated external defibrillator (AED) is a portable defibrillation device. Most ambulances carry AEDs. They are also frequently found in many public places, such as sports complexes and restaurants.
Defibrillation should be done as soon as equipment is available.
Anti-arrhythmic drugs may be given intravenously with continued resuscitation attempts when a person continues to fibrillate.
If the heart’s rhythm is stabilized by defibrillation, anti-arrhythmic drugs can be given to maintain the heart’s rhythm.
An implantable cardioverter defibrillator (ICD) can be surgically placed in the chest to help prevent ventricular fibrillation. An ICD continuously monitors the heart’s rhythm. If it detects an abnormal beat, it automatically sends electrical impulses to restore the heart’s normal rhythm.
To help reduce your chances of ventricular fibrillation:
If a person is at high risk of ventricular fibrillation, an implantable cardioverter defibrillator (ICD) can be surgically placed in the chest to help stop ventricular fibrillation. In addition, anti-arrhythmic drugs may be given to try to prevent a future episode.
American Heart Association
Heart Rhythm Society
Canadian Heart Rhythm Society
Heart and Stroke Foundation of Canada
ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Circulation. 2006;114(10):e385-e484.
CPR and first aid. American Heart Association website. Available at: http://www.heart.org/HEARTORG/CPRAndECC/CPR_UCM_001118_SubHomePage.jsp.
Risk factors & prevention. Heart Rhythm Society website. Available at: http://www.hrsonline.org/Patient-Resources/Risk-Factors-Prevention#axzz3NOr35s6f.
Ventricular fibrillation (VF). Merck Manual Professional Version. Available at: http://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/ventricular-fibrillation-vf.
What is an automatic external defibrillator? American Heart Association website. Available at: http://www.heart.org/idc/groups/heart-public/@wcm/@hcm/documents/downloadable/ucm_300340.pdf.
Last reviewed November 2020 by EBSCO Medical Review Board Michael J. Fucci, DO, FACC Last Updated: 12/20/2020