Atrial Fibrillation: By Age, Sex, and More

Medically Reviewed by James Beckerman, MD, FACC on July 11, 2022
5 min read

At least 3 million to 6 million people have atrial fibrillation, also known as AFib. It’s one of the most common types of arrhythmia, or irregular heart rhythm. And experts estimate the condition will affect 6 million to 12 million Americans by 2050.

What causes it? Is it more common in men or women? Does your lifestyle play a role? Epidemiology looks to answer these and other questions. It’s a branch of science that studies how conditions, diseases, and events affect different groups of people and why.

Anything that thickens, thins, or scars your heart can trigger the condition. So can inflammation of heart tissue or changes in electrical signaling.

Things that up your risk for atrial fibrillation include:

Family history. Up to 30% of people with the condition have a relative with it, too. If you have family members with atrial fibrillation, know the signs and get treatment ASAP. Untreated atrial fibrillation can lead to a stroke, heart failure, or fatigue that doesn’t go away.

Sex. AFib generally affects more men than women. But after age 75, 60% of people with AFib are women. Women over age 75 may be more at risk for blood clots and have greater challenges with treatment. That’s because some drugs can trigger atrial fibrillation.

Ancestry. People of European heritage are more likely to have AFib than are African Americans, Asians, and Hispanics. But African Americans are more likely to die from it. Experts don’t know if this is because of genetics or the environment.

High blood pressure. Long-term, uncontrolled high blood pressure puts you at higher risk for atrial fibrillation than those with blood pressure in the normal range. One in six cases of atrial fibrillation have been caused by high blood pressure.

Age. The risk of atrial fibrillation for both men and women goes up with age. This could be because the heart is exposed to more risk factors over time. Over the years, electrical and structural changes – such as thickening of the heart wall – make it harder for blood to flow.

Heart surgery. Atrial fibrillation is the most common complication after heart surgery. It occurs in 15% to 40% of patients, usually shortly after surgery. After treatment, the heart typically goes back to its normal rhythm within 6 or so weeks.

Heart disease. People with these issues should keep an eye out for symptoms:

Wolff-Parkinson-White syndrome (WPW). When the electrical signals reach the lower chambers of the heart before they should, they bounce back to the upper chambers. This can cause atrial fibrillation.

Supraventricular tachycardia (SVT). When the electrical signals in the heart’s upper chamber don’t work the way they’re supposed to, it can affect the part of your heart that serves as a pacemaker. This may cause a faster than normal heartbeat, which keeps the heart from filling completely between beats.

Athletes. Research suggests that high-intensity and high-volume exercise raises your risk of atrial fibrillation. It’s difficult to pinpoint the specific cause, but it could be from excessive strain of blood flow in the heart and stretching of the arteries. The risk of AFib is higher in younger athletes, compared with older ones.

Obesity. Weight loss can help ease symptoms, how severe the disease is, blood volume in the heart, and reduce some thickness of the heart wall.

Binge drinking. Having more than five drinks in 2 hours for men, or four drinks in 2 hours for women, ups your risk.

Sleep apnea. In this sleep disorder, breathing repeatedly stops during the night for various reasons. Studies have shown a strong link between sleep apnea and AFib, although it is not a proven cause.

Other medical conditions. Thyroid problems, diabetes, and asthma can also trigger AFib.

A study that tracked AFib rates from 2006 to 2018 shows the number of new cases rising over the years. Researchers think advances in technology may be one reason for this. As tests get better, more atrial fibrillation is diagnosed. Other reasons may be that the population is getting older and surviving heart conditions more. Also, over time, people are getting more risk factors, such as obesity and hypertension.

Some forms of AFib can be treated with lifestyle changes, such as staying active and maintaining a healthy weight, reducing stress, eating heart-healthy foods, and reducing salt in your diet to help lower blood pressure. Of course, doctors recommend limiting alcohol, stopping smoking, and steering clear of illegal or street drugs.

Your doctor may want to use a type of medication or procedure to even your heart rate or make your heart beat more slowly. Here are some choices:

Beta-blockers slow the rate at which your heart’s lower chambers pump blood and reduce symptoms. These are not recommended for people with COPD, arrhythmia, or low blood pressure.

Blood thinners prevent blood clots that may lead to a stroke. If you have a bleeding disorder or history of bleeding problems, discuss this with your doctor.

Calcium channel blockers control the rate at which your heart’s lower chambers pump blood.

Digitalis and digoxin control the rate of blood pumped through the body. These can cause other types of arrhythmias, so discuss the risks with your doctor.

Electrical cardioversion is a procedure sometimes used along with medications. It uses electrical shocks to restore a normal heart rhythm. This procedure is done while under general anesthesia, so you will not feel any pain. There are risks – blood clots can travel to other organs and cause a stroke, or other arrhythmias – but the doctor will take precautions to avoid these side effects.

A pacemaker may be implanted if the AFib is caused by a slow heartbeat or another type of arrhythmia.

With catheter ablation, a cardiologist inserts a small tube with wires through your vein to your heart. The hot or cold energy destroys the tissue that is causing the arrhythmia. This procedure may result in a stroke, and the arrhythmia may return in the first few weeks after the procedure.

Surgical ablation destroys the damaged heart tissue that is sending out the faulty signals. During ablation, the surgeon can also plug or close off a part of the heart to prevent clots from forming in the area. If these closures leak, it could lead to clotting.

Most people who are treated for AFib can have normal, active lives. It is important to get treated for AFib or talk with your doctor if you have symptoms.