Overview

What Is Atrial Fibrillation?

Your heart’s electrical system (called the conduction system) sends signals from the top chambers of heart (atria) at regular intervals to control the rhythm of your heartbeat.

Atrial fibrillation is an irregular heartbeat that prevents the atria from contracting normally. Instead, the atria quiver, decreasing the amount of blood ejected from the heart with each heartbeat.

Caused by abnormal, irregular electrical signals from the conduction system, atrial fibrillation is a complex condition affecting close to five million people in the United States. It is responsible for 15 to 20 percent of all strokes. It is more common in people who are 65 and older, more often affecting men than women. There is a 1 in 4 risk that you or a loved one will develop atrial fibrillation. The earlier atrial fibrillation is diagnosed and treated, the more successful we are in retuning a patient to a “normal” rhythm.