Atrial Fibrillation: Symptoms and Causes

Symptoms of atrial fibrillation (AF) can vary from person to person. Some people find that it puts a crimp on everyday activities, while others are short of breath after just a little physical exertion and find that they can’t concentrate.

Not everyone who develops AF will experience symptoms, but for those who do, they can range from mild to severe and can include the following:

• Fatigue

• Palpitations (irregular, rapid, or a pounding sensation in the neck or chest)

• Shortness of breath

• Lightheadedness

• Dizziness

• Chest pain/discomfort

• Syncope (transient loss of consciousness or fainting)

Causes of atrial fibrillation

Multiple factors can contribute to the development of AF and the abnormal functioning of the heart’s upper chambers. These include high blood pressure, coronary heart disease, cardiomyopathy (progressive degeneration of the heart muscle), obesity, sleep apnea, and valvular disorders.

AF is also associated with diabetes, an overactive thyroid (hyperthyroidism), and pneumonia, and it commonly develops after cardiac surgery.

Age is a key factor—AF is rare before age 50, whereas 1 in 10 people age 80 have it. AF is also more common in men than in women, and it is more common in whites than blacks. It is also well established that AF can run in families. The presence of a first-degree relative with AF results in a doubling of the likelihood that other members of the family will develop the condition. Although some specific genetic abnormalities have been reported in some families with AF, this is very unusual and there is currently no clinical role for genetic testing in patients with AF.

An AF visualization

Here’s a good way to visualize what goes on when you have AF: You’re out in the middle of a placid lake in a canoe. You drop a stone overboard, causing the water to ripple out in gentle circles away from the boat. That stone represents your atrioventricular (AV) node and it controls the rhythmic water ripples, which are the heartbeats. When the water is calm again, toss a handful of smaller stones into the water. A chaotic pattern of uncoordinated water ripples develops. This represents your heartbeat in atrial fibrillation.

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HealthAfter50 was published by the University of California, Berkeley, School of Public Health, providing up-to-date, evidence-based research and expert advice on the prevention, diagnosis, and treatment of a wide range of health conditions affecting adults in middle age and beyond. It was previously part of Remedy Health Media's network of digital and print publications, which also include HealthCentral; HIV/AIDS resources The Body and The Body Pro; the UC Berkeley Wellness Letter; and the Berkeley Wellness website. All content from HA50 merged into in 2018.