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Atrial Fibrillation

Sometimes the heart's electrical signals can lose their regular pattern. With atrial fibrillation, many parts of the atria, the heart's two upper chambers, start emitting uncoordinated electrical signals. The electrical impulses cause irregular, erratic and unusually fast heartbeats. An estimated 2 million Americans are living with atrial fibrillation, making it the most common serious heart rhythm abnormality.

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.

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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.

  • Electrocardiogram — The electrocardiogram (ECG or EKG) records the heart's electrical activity. Small patches called electrodes are placed on your chest, arms and legs, and are connected by wires to the ECG machine. Your heart's electrical impulses are translated into a wavy line on a strip of moving paper, enabling doctors to determine the pattern of electrical current flow in the heart and to diagnose arrhythmias and heart damage.
  • Holter Monitor — A holter monitor is a small, portable machine that you wear for 24 hours. It enables continuous recording of your ECG as you go about your daily activities. You will be asked to keep a diary log of your activities and symptoms. This monitor may detect arrhythmias that might not show up on a resting EKG that only records for a few seconds.
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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.

Medications

Certain anti-arrhythmic drugs change the electrical signals in the heart and help prevent abnormal sites from starting irregular or rapid heart rhythms.

Follow-up Electrophysiology Study

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.

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Reviewed by health care specialists at UCSF Medical Center.