Ventricular fibrillation 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 "flutter" rather than beat, causing the heart to pump little or no blood. Ventricular fibrillation is life-threatening and requires prompt treatment. Collapse and sudden cardiac death will follow in minutes unless medical help is provided immediately. If treated in time, ventricular fibrillation can be converted into a normal rhythm by shocking the heart with a device called a defibrillator.
An effective way to correct life-threatening rhythms is by using an electronic device called an implantable cardioverter defibrillator, which shocks the heart to normalize the heartbeat if the heart's own electrical signals become disordered.
An abnormal heart rhythm is a change in either the speed or the pattern of the heartbeat — the heart may beat too slowly, too rapidly or irregularly. When the heart beats too slowly, too little blood is pumped out to the rest of the body. When the heart beats too quickly, it cannot fill completely so the body doesn't receive the blood volume it needs to function properly. Slow heart rates are called bradycardias. Fast heart rates are called tachycardias.
The heart is made up of four chambers. The upper chambers, called the atriums, receive and collect blood. The lower chambers, called the ventricles, pump blood to the body. Working together, the chambers of the heart move life-sustaining blood throughout the body.
If your doctor suspects that you may have an arrhythmia, he or she will order one or more of the following diagnostic tests to determine the source of your symptoms.
Depending on the type and severity of your arrhythmia, and the results of various tests including the electrophysiology study, there are several treatment options. You and your doctor will decide which one is right for you.
Certain anti-arrhythmic drugs change the electrical signals in the heart and help prevent abnormal sites from starting irregular or rapid heart rhythms.
To make sure the medication is working properly after two or more days in the hospital, you may be brought back to the laboratory for a follow-up study. Our goal is to find the drug that works best for you.
Reviewed by health care specialists at UCSF Medical Center.