What Is AFib?

Atrial fibrillation (AFib) is a heart condition in which the two small upper chambers of your heart, called the atria, beat too fast and in an irregular rhythm. This causes them to be out of sync with the lower chambers of your heart, called the ventricles. When the atria and ventricles don’t work together as they should, blood doesn’t get pumped through the heart completely—like a sponge that hasn’t been fully squeezed out. This can cause blood to pool and form clots inside your heart. If a blood clot moves through your bloodstream from your heart to your brain, it can cause a stroke, which can be life threatening.

How does AFib cause a stroke?

Watch this short video and learn how an irregular heartbeat can cause a clot to form and lead to a stroke.

What causes AFib?

Your heartbeat is controlled by electrical signals in your heart muscle. In a normal heart, the electrical signals travel like a wave from the top of the heart to the bottom—letting it know when to contract and relax in a steady and consistent rhythm. In people with AFib, these electrical signals may be interrupted, disorganized, or irregular. Without the proper signals, the heart cannot pump blood normally.

When I was first diagnosed with AFib, the doctor gave me a concise description of what it is.

Hear what Paul’s doctor told him about AFib.

What does having AFib mean for my overall health?

While an irregular heartbeat may feel scary, AFib itself is not usually life threatening. Actually, the most serious complication of AFib is stroke—which can, in fact, be life threatening. If blood pools and forms a clot inside your heart, the clot may travel through your bloodstream from your heart to your brain. There, it blocks blood flow and oxygen, causing a stroke. This is why it’s so important to recognize the symptoms of AFib and seek treatment right away. It’s also important to learn the symptoms of a stroke and what to do in a stroke emergency.

Stroke risk can be reduced with a blood thinner like XARELTO®.

AFib and cardiovascular health

AFib can also have other serious effects on your health because it involves your cardiovascular system. Cardiovascular means “having to do with the heart and blood vessels."

Your cardiovascular system is also known as the circulatory system. Your heart, arteries, veins, and lungs all work together to circulate nutrients and oxygen-rich blood to every single part of your body. Because of this connection, a problem like AFib can lead to other medical problems like heart failure, chronic fatigue, other heart-rhythm issues, or inconsistent blood supply.

There is also a link between AFib and coronary artery disease (CAD). Because AFib and CAD have shared risk factors, some people with AFib may also have CAD. In fact, some studies show that as many as 47% of people with AFib also have CAD.

So if you have AFib, the best thing you can do to take care of yourself is to learn all you can about your condition, take your medicine as prescribed, eat a more heart-healthy diet, and try to exercise more—even if it’s just a walk around the block. Learn more about living well with AFib.

Infographic showing the cardiovascular system and how blood flows from the heart to body to lungs