Atrial Fibrillation (Afib)

How your heart normally works

Your heart pumps blood to the rest of your body. During each heartbeat, your two atria contract, followed by your two lower chambers (ventricles). These actions, when timed perfectly, allow your heart to work as an efficient pump. Your heart’s electrical system controls the timing of your heart’s contractions. And your sinoatrial (SA) node is normally in charge of that electrical system. This node is located in your right atrium. When your SA node fires an impulse, electrical activity spreads through your right and left atria (“atrium” is singular and “atria” is plural). Both atria then contract and force blood into your ventricles.

The impulse then travels to the atrioventricular (AV) node, located near the middle of your heart. From there, the impulse moves to your ventricles, causing them to contract and pump blood out of your heart to your lungs and the rest of your body. This process repeats with every heartbeat. The SA node directs the timing of the electrical impulses and keeps your heart pumping smoothly.

You can think of your SA node as the conductor of an orchestra. Your SA node is responsible for keeping your heart beating at the proper pace and rhythm. Likewise, an orchestra conductor directs all the musicians to keep the music flowing at the right tempo, sometimes faster and sometimes slower.

Normally, your SA node adjusts to your level of activity. For example, it increases the rate of impulses when you exercise and decreases the rate when you sleep. With the SA node conducting your heart’s rhythm, you are in “normal sinus rhythm.” This means your heart is beating at a regular rhythm and pace, about 60 to 100 times per minute.

What happens when you’re in Afib

If you have atrial fibrillation, your SA node isn’t directing your heart’s electrical rhythm. Instead, many different impulses rapidly fire at the same time, causing a fast, chaotic rhythm in your atria. As a result, your atria can’t contract or pump blood effectively into your ventricles. Your ventricles contract irregularly, causing a rapid irregular heartbeat.

It’s as if in the middle of a concert, two more conductors walked onto the stage and started waving their batons. The musicians would no longer know who to follow or what to do. The music would lose its rhythm and harmony.

Fortunately, there are many ways to bring back your heart’s rhythm and harmony if you have Afib. It all starts with a visit to your healthcare provider, who can run some tests and make a diagnosis.

How common is atrial fibrillation?

Some researchers have called Afib the “new cardiovascular disease epidemic of the 21st century.” Afib is especially common among older adults. Over 33 million people age 55+ have been diagnosed globally. Estimates predict that 12 million people in the U.S. will have Afib by 2030. Afib causes nearly half a million yearly hospitalizations in the U.S. and leads to more and more deaths with each passing year.

Who does atrial fibrillation affect?

While Afib can affect anyone, it’s more common among people of European descent. However, Black people who have Afib are more likely to have serious complications such as stroke or heart failure. People assigned female at birth (AFAB) are more commonly diagnosed than people assigned male at birth (AMAB).

What causes atrial fibrillation to start?

Changes or damage to your heart’s tissue and electrical system cause atrial fibrillation. Usually, coronary artery disease or high blood pressure causes those changes. Often a trigger heartbeat causes atrial fibrillation to begin. But sometimes it’s hard to know the cause of that triggered heartbeat. For some people, there is no identifiable cause. Research is constantly providing new information to help us learn more about the

Afib often runs in families. So, if a close family member has Afib, you have a “family history” and therefore a higher chance of developing it, too.

Can atrial fibrillation be caused by anxiety?

We don’t fully know the connections between atrial fibrillation and anxiety. Research has identified Afib as a cause of anxiety (if you have Afib, you might worry about your symptoms or quality of life). But few studies have explored anxiety as a cause of Afib. We do know that anxiety can raise your risk of cardiovascular disease and causes a 48% higher risk of cardiac death. However, we need more research to find out if anxiety disorders can cause Afib.

How is atrial fibrillation diagnosed?

To diagnose atrial fibrillation, your healthcare provider will first ask you some questions. You’ll share information about your diet and physical activity, family history, any symptoms you’ve noticed and risk factors. It’s OK if you don’t know all the answers but share as much as you can. Your experiences and knowledge are essential tools to help your provider make a diagnosis. Your provider will then give you a physical exam that includes:

Listening to your heart rhythm with a stethoscope.

Checking your pulse and blood pressure.

Checking the size of your thyroid gland to identify thyroid problems.

Looking for swelling in your feet or legs to identify heart failure.

Listening to your lungs to detect heart failure or infection.

This exam will help your provider understand your baseline health and how your body is functioning.

Tests to diagnose atrial fibrillation

In addition to the physical exam, your provider may run some tests to make an atrial fibrillation diagnosis. These tests include:

Electrocardiogram (EKG or ECG). An EKG is usually the first test. It’s painless and takes about three minutes. It measures and records your heart’s electrical signals and allows your provider to see if your heart is beating normally.

Echocardiogram (echo). An echo uses ultrasound technology to show your heart’s movement. It can reveal problems with blood flow and heart muscle contractions.

Blood tests. Sometimes, imbalances in our blood can cause Afib. Simple blood tests can show your potassium and thyroid hormone levels and can help your provider choose the best medicines for you based on your liver and kidney function.