Ventricular Fibrillation

Ventricular fibrillation (VF) is a condition in which the heart's electrical activity becomes disordered. When this happens, the heart's ventricles — the lower chambers that pump blood — contract in a rapid, unsynchronized way. The ventricles "quiver" rather than beat, causing the heart to pump little or no blood.

VF is life-threatening and requires prompt treatment. Without medical treatment, collapse and sudden cardiac death will occur. However, VF can be treated with a medical device called an implantable cardioverter defibrillator (ICD), which brings the heartbeat back to a regular rhythm.

Ventricular fibrillation may cause the following symptoms:

  • Chest pressure or pain
  • Fatigue
  • Lightheadedness or dizziness
  • Palpitations, which can be skipping, fluttering or pounding in the chest
  • Shortness of breath

Ventricular fibrillation (VF) may occur spontaneously with unpredictable timing, and specialized tests are needed to make an accurate diagnosis. If your child's doctor suspects your child has an arrythmia caused by ventricular fibrillation, he or she will order one or more of the following diagnostic tests:

  • Electrocardiogram (ECG or EKG) — An ECG records the heart's electrical activity. Small patches called electrodes are placed on your child's chest, arms and legs, and are connected by wires to the ECG machine. The electrical impulses of your child's heart are translated into a graph or chart, enabling doctors to determine the pattern of electrical current flow in the heart and to diagnose arrhythmias.
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Treatment for ventricular fibrillation depends on the type and severity of the condition and the results of the diagnostic tests, such as the electrophysiology (EP) study. You and your child's doctor will decide which treatment is right for your child.

A medical device called an implantable cardioverter defibrillator (ICD) is one possible treatment. While not a cure for heart rhythm problems, an ICD stops a very fast heart rhythm and brings the heartbeat back to normal. It may prevent sudden cardiac death. Defibrillator paddles may either be applied to the chest externally or the defibrillator may be implanted internally, which is known as an internal cardiovertor defibrillator (ICD). An ICD is the most common therapy for children with VF.

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Reviewed by health care specialists at UCSF Benioff Children's Hospital.

Related Information

UCSF Clinics & Centers

Heart Center

Arrhythmia Center
1825 Fourth St., Sixth Floor
San Francisco, CA 94158
Phone: (415) 514-2783
Fax: (415) 353-4144
Appointment information

Pediatric Heart Center Clinic at Mission Bay
1825 Fourth St., Sixth Floor
San Francisco, CA 94158
Phone: (415) 353-2008
Fax: (415) 353-4144
Appointment information

Cardiac Intensive Care Unit
1975 Fourth St., Fourth Floor
San Francisco, CA 94158
Phone: (415) 353-1955
Fax: (415) 353-9144