What does asthma have to do with atrial fibrillation?

More than you might think.

That’s the conclusion of a new study that associates the potentially life-threatening heart condition with the ailment that causes difficulty in breathing.

The Centers for Disease Control and Prevention (CDC) reports that almost 10 percent of Americans live with asthma.

Complications can include high blood pressure, lung infections like pneumonia, and even respiratory failure.

Asthma rates have surged worldwide over the past 30 years.

The new research, published in JAMA Cardiology, states that poorly controlled asthma also brings a significantly increased risk of atrial fibrillation (AFib).

Although previous research had linked asthma with the risk of coronary heart disease, stroke, and heart failure, the study authors report that no previous studies had assessed the dose-response (change caused by differing levels of exposure) association between asthma control and AFib risk.

In this study, the researchers relied on information from a larger group of patients than previous studies (more than 54,000) and followed up for almost six years.

Only patients who had not been previously diagnosed with AFib were included.

The researchers also excluded factors that potentially cause AFib, such as heart disease or a history of smoking.

They said they did this to find the clearest association between asthma, levels of asthma control, and AFib.

What is AFib?

AFib is an irregular and rapid heart beat that can significantly increase your risk of stroke.

It’s the most common problem with someone’s heart rate.

According to the American Heart Association (AHA), when the heart's two upper chambers contract quickly and out of sync, the heart begins to quiver or fibrillate. This can cause blood clots to form in the heart.

These blood clots may circulate to other organs, especially the brain, and block blood flow. In the brain, this can cause a stroke.

When it’s not treated, this condition can eventually weaken your heart, leading to heart failure.

The symptoms of AFib include shortness of breath, fatigue, and chest pain, although you can also have AFib and experience no symptoms at all.

Asthma and AFib risk

After adjusting for sex and age, study participants with uncontrolled asthma at the start of the study had an estimated 74 percent increased risk of developing AFib compared with the participants with no asthma.

The risk of AFib was significantly lower in participants with partly and completely controlled asthma.

Dr. Mark Millard, a pulmonologist affiliated with Baylor University Medical Center in Texas, read the study and told Healthline “However, when you ask how many people who had asthma also experienced atrial fibrillation, compared with those without asthma, I find that the data indicates a little less than double the risk of atrial fibrillation, especially in people taking medication for their asthma.”

The researchers report as many as 98 percent of patients with severe asthma have unbalanced levels of potassium associated with the use of drugs called β2-agonists like Albuterol.

This can cause health issues that include heart trouble.

Millard says “β2-agonists like Albuterol can increase heart rates, reduce potassium, and even increase glucose levels in the blood stream when given in high doses.”

“The best way to prevent this is by avoiding overuse and only take it as prescribed,” adds Dr. Sadia Benzaquen, director of Interventional Pulmonology at the University of Cincinnati College of Medicine.

These drugs open the airways by relaxing lung muscles. Patients with severe asthma in the study relied on these medications. The study authors admit that this is one factor that they couldn’t exclude from their results.

However, researchers insist that the higher AFib risk among patients with active and uncontrolled asthma could not be explained by the use of these drugs.

They conclude that the questions asked about asthma symptoms and medication use enabled them to rule out the effects of asthma drugs.

Taking control of asthma

Besides taking asthma medication as instructed, Millard explains that reducing exposure to those things that trigger an attack is also an important part of asthma control.

“This may involve avoiding allergen exposure from cigarette smoke, plug-in air fresheners, or any other things you know will trigger an attack,” he said.

Benzaquen considers maintaining a healthy weight and regular exercise to be just as important.

“Getting regular exercise, eating a healthy diet and avoiding obesity will help significantly reduce the incidence of asthma attacks,” Benzaquen said.

Millard concludes “Atrial fibrillation occurred in less than five percent of the entire study population, which is pretty low.”

He emphasizes that “It’s important to understand that this study does not prove that all people with asthma are going to get atrial fibrillation, only that the risk is increased.”