Every year, more Americans are diagnosed with atrial fibrillation (AFib for short). And every day, people continue to test positive for COVID-19 – including first, second and even third-timers.

But is there a link between AFib and COVID?

Aneesh Tolat, MD, a cardiac electrophysiologist with Hartford HealthCare’s Heart & Vascular Institute, explains.

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What exactly is AFib?

AFib is an irregular, often rapid, heart rhythm that can lead to stroke and heart failure.

It’s serious, but it’s also increasingly common: Once you cross age 40, you have a one in four chance of developing the condition — a likelihood that increases with age.

Like other heart disease, AFib is related to inflammation in the body. It can come on over time or all at once, triggered by everything from stress to obesity to an intense workout.

That includes illness, especially severe illness.

> Related: Eight Signs You Might Have a Heart Arrhythmia

AFib is on the rise.

As the population ages and more U.S. adults acquire risk factors like obesity, hypertension and diabetes, “we’re seeing a rise in AFib pretty much across the spectrum,” says Dr. Tolat.

So don’t ignore the signs: a racing heart, irregular heartbeat, or even just feeling fatigued or lightheaded. Smart watches can help by alerting you to an irregular heartbeat. So can your doctor with a simple stethoscope exam — another reason not to skip routine wellness exams.

“If you notice any abnormalities in your heartbeat, seek medical attention,” says Dr. Tolat.

> Related: Could Your Heart Murmur Be Aortic Stenosis?

Because AFib has many triggers, it’s not unusual in hospitalized patients.

“There’s a lot of context for AFib to be seen in the hospital, whether with the flu or pneumonia, or after cardiac surgery,” says Dr. Tolat. “These are all inflammatory triggers for AFib.”

But for the most part, when AFib shows up in hospitalized patients, it’s not linked to a higher risk of in-hospital death.

With one recent COVID study, it was.

The study found that one in 20 patients hospitalized with COVID developed atrial fibrillation (AFib) during their hospital stay, and nearly half of them went on to die in the hospital.

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New-onset AFib was a sign of severe illness in COVID patients.

Since AFib is related to inflammation, and COVID can cause inflammation, “it’s not surprising to see AFib in one in 20 hospitalized COVID patients,” says Dr. Tolat.

But the recent study, which used data from the American Heart Association (AHA), also uncovered some more concerning trends.

  • The patients with new-onset AFib had longer hospital stays, and were more likely to need ICU care and intubation.
  • About 45% of patients with new-onset AFib died while in the hospital.

Did AFib contribute to their death? We can’t be sure. All of these patients were seriously ill before AFib came into the picture. And most had other risk factors for severe COVID outcomes, like advanced age or an underlying condition like diabetes.

The takeaway

Here’s what we do know: In this study, AFib certainly signaled severe illness.

“Here it really raises the concern over a very ill patient,” says Dr. Tolat.

Researchers will continue to study the connection between COVID and AFib, including whether individuals who’ve recovered from milder case of COVID are at greater risk for the heart condition

In the meantime – however you keep track of your heart health, keep AFib top of mind.