Arrhythmia

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.

• Other Abnormal Heart rhythms
• Arrhythmia -- Signs and Symptoms, Diagnosis and Treatment
• UCSF Cardiac Electrophysiology and Arrhythmia Service

Reviewed by health care specialists at UCSF Medical Center.
Last updated May 8, 2007

This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.