Atrial fibrillation (AFib) is a common heart rhythm disorder that causes an irregular and often rapid heartbeat. In a normal heart, the resting heart rate is usually 60 to 100 beats per minute. With AFib, the heart rate may rise to 100 to 175 beats per minute or higher.
AFib is the most common type of abnormal heart rhythm (arrhythmia). When the heart beats irregularly, it may not pump blood as effectively as it should. Over time, this can increase the risk of serious complications such as blood clots, stroke and heart failure.
AFib can affect people of any age, but it becomes more common as people get older. With early diagnosis and the right treatment plan, many people with AFib can manage symptoms and protect their heart health.
To understand AFib, it helps to know how the heart normally works.
The heart has four chambers:
The heartbeat normally starts in a group of specialized cells in the sinoatrial (SA) node, located in the upper right chamber of the heart.
This natural pacemaker sends electrical signals that travel through the heart and cause the chambers to contract in a coordinated rhythm.
In atrial fibrillation, these electrical signals become disorganized and chaotic. Instead of contracting normally, the atria quiver or fibrillate. This can lead to:
Because blood may not move smoothly through the atria, it can pool and form clots. If a clot travels to the brain, it can cause a stroke.
AFib may lead to complications including:
Some people with atrial fibrillation do not notice symptoms, especially in the early stages. In other cases, symptoms may come and go.
Because AFib can increase the risk of stroke and other heart problems, early detection is important. Regular checkups and heart health screenings may help identify abnormal heart rhythms before complications develop.
Finding AFib early and starting treatment can help:
Some people with AFib have no symptoms at all, while others may notice mild or severe symptoms that affect daily activities.
Common AFib symptoms include:
A fast, irregular or fluttering heartbeat. Palpitations may come and go or last longer periods of time.
You may feel breathless during physical activity or when lying down. This happens because the heart may not pump oxygen-rich blood efficiently.
Many people feel unusually tired or weak, even with normal daily activities.
You may feel dizzy, especially when standing up quickly or during exertion.
Chest discomfort is less common but may occur. It can range from mild to severe.
If you notice symptoms of atrial fibrillation, talk with a health care provider. Diagnostic tests such as an electrocardiogram (ECG) or a Holter monitor may be used to track your heart rhythm and confirm whether AFib is present.
Call 911 or seek emergency care immediately if you experience:
These symptoms may indicate a serious heart problem or stroke and require immediate medical attention.
Atrial fibrillation may develop due to changes in the heart’s structure or electrical system. Several health conditions can increase the likelihood of AFib.
Common causes and triggers include:
High blood pressure can strain the heart and cause structural changes that affect its electrical signals.
Coronary artery disease, heart valve disorders, congenital heart defects and previous heart surgery can contribute to AFib.
Conditions such as hyperthyroidism can affect metabolism and increase heart rate.
Sleep apnea, obesity, diabetes, lung disease, kidney disease, pneumonia, viral infections and complications after surgery may increase the risk.
Several factors can raise your chances of developing AFib.
Risk increases with age, especially after 65.
Having relatives with AFib or other heart rhythm disorders may increase your risk.
Smoking, stimulant drugs and alcohol use - especially binge drinking - can trigger AFib.
Long-term stress may affect hormone levels and stimulate the nervous system.
Abnormal levels of potassium, sodium, calcium or magnesium can interfere with normal heart rhythm.
Healthy lifestyle habits can help protect your heart and lower the risk of AFib and related complications.
Helpful strategies include:
If you have risk factors for AFib, your provider may recommend heart rhythm monitoring or screening to detect problems early.
At Banner Health, our heart specialists provide advanced care for atrial fibrillation, from early diagnosis to long-term management.
Your care team may include cardiologists and heart rhythm specialists (electrophysiologists) who offer treatments such as:
Our goal is to control your heart rhythm, reduce complications and help you live well with AFib.
Explore atrial fibrillation diagnosis and treatment options at Banner Health.
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