Insomnia and stressful life events like divorce may contribute.

• The risk of developing an irregular heartbeat increases after menopause.
• New research finds that stress and insomnia may play a role.
• Having an irregular heartbeat raises the risk of developing a slew of health conditions.

Cardiovascular disease is the leading cause of death for women in the U.S., and research has found that the risk of developing heart disease goes up after a woman goes through menopause. Now, a new study has determined that up to one in four women develop an irregular heartbeat after menopause—that’s a whopping 25%—likely associated with insomnia and stressful life events like divorce.

The study, which was published in the Journal of the American Heart Association, analyzed data from 83,736 women with an average age of about 64 who participated in the Women’s Health Initiative, a long-term national health study that focuses on strategies for preventing heart disease, breast and colorectal cancer, and osteoporosis in postmenopausal women.

Over the course of about 10 years, there were 23,954 cases of atrial fibrillation, which is an irregular and often very fast heartbeat. Researchers found that the risk of atrial fibrillation went up in women who had higher ratings in a “Stress Cluster,” which included stressful life events (like divorce), depressive symptoms, and insomnia. The greatest risk was in women who had insomnia and stressful life events—the researchers concluded that they were “significantly associated” with atrial fibrillation in postmenopausal women.

But what does this mean and what options are available for women? Doctors break it down.

Why Might Someone Develop An Irregular Heartbeat After Menopause?

Research from the American Heart Association (AHA) has already found that women have a “notable increase in the risk” for heart disease after menopause. The AHA says that “distinct patterns of sex hormone changes” as well as changes in body composition and lipids (fatty compounds in the body) seem to play a role.

David Slotwiner, M.D., chief of cardiology at NewYork-Presbyterian Queens, and assistant professor of clinical medicine and of population health sciences at Weill Cornell Medicine, says the drop in estrogen levels during menopause can have a direct impact on the cardiovascular system. “Estrogen plays a role in regulating the autonomic nervous system which controls the heart rate and can affect the heart rhythm,” he explains. As estrogen levels go down, some women may have irregular heartbeats or feel like their heart is racing or fluttering, he says. This, Dr. Slotwiner notes, “can be distressing and alarming,” especially for women who have never had them before.

But this study also found that stress—both mental and physical—seems to play a role, points out Sarina van der Zee, M.D., a board-certified cardiac electrophysiologist and cardiologist at Providence Saint John’s Health Center in Santa Monica, CA.

“Stress in many forms is a known trigger for atrial fibrillation,” Dr. van der Zee says. “The stress response, including hormonal activation and inflammation, impacts the cardiovascular system directly and affects other aspects of health including sleep, weight, and alcohol use, which are known to be atrial fibrillation risk factors.”

The link between insomnia and menopause isn’t new: Data from the National Institutes of Health (NIK) found that sleep disturbances like insomnia vary from 16% to 42% before menopause, from 39% to 47% during perimenopause (the period leading up to menopause), and from 35% to 60% after menopause. Researchers have theorized changing reproductive hormone levels, circadian rhythm abnormalities, mood disorders, lifestyle, and other medical conditions may play a role.

“Hormones play a fundamental role in healthy and continuous sleep,” says W. Christopher Winter, M.D., a neurologist and sleep medicine physician with Charlottesville Neurology and Sleep Medicine and host of the Sleep Unplugged podcast.

The AHA also notes online that being an older adult is a risk factor for atrial fibrillation, but doesn’t specifically call out menopause as a reason.

Lead study author Susan X. Zhao, M.D., a cardiologist at Santa Clara Valley Medical Center in San Jose, CA., says that she’s noticed in her patients that poor sleep and negative feelings can raise the risk of an irregular heartbeat in postmenopausal women, even if someone is in “very good physical health.”

Why Is Atrial Fibrillation Concerning?

Atrial fibrillation on its own doesn’t usually have harmful consequences, the AHA notes. But it may raise your risk of a slew of serious health conditions. Those include:

• Stroke
• Heart failure
• Chronic fatigue
• Other heart rhythm problems
• Inconsistent blood supply

“Atrial fibrillation affects health and quality of life,” Dr. Zhao says. “It also carries a high price tag, due to the sheer volume of people afflicted with atrial fibrillation.”

What Are The Symptoms Of Atrial Fibrillation?

It’s possible to have atrial fibrillation and not notice it, according to the Mayo Clinic. But, if you have symptoms, they can include:

• Feelings of a fast, fluttering, or pounding heartbeat
• Chest pain
• Dizziness
• Fatigue
• Lightheadedness
• Reduced ability to exercise
• Shortness of breath
• Weakness

There is a range of atrial fibrillation: Some people may have symptoms that last for a few minutes to a few hours and then go away; others can have a constant irregular heartbeat.

How Is AFib Treated?

Treatment for atrial fibrillation can vary. It may include lifestyle changes like getting regular physical activity, eating a heart-healthy diet that’s low in salt, saturated fats, trans fats, and cholesterol, managing high blood pressure and cholesterol, maintaining a healthy weight, and avoiding excessive amounts of alcohol and caffeine, the AHA says.

But atrial fibrillation may also require medications like beta blockers, blood thinners, and calcium channel blockers to control the speed of your heart, restore your normal rhythm, and prevent blood clots, the Mayo Clinic says. A procedure called cardioversion may be used to try to reset the heart rhythm if this is your first episode of atrial fibrillation and, if medication and other treatments don’t help, surgery may be needed, the Mayo Clinic says.

If you’re having symptoms of atrial fibrillation, Dr. Slotwiner says it’s important to contact your doctor and be prepared to answer questions about when you have irregular heartbeats, how long they last, and other symptoms you may experience. Your doctor should be able to give you a full evaluation and recommend next steps from there.