What is AFib? Danger signs and treatments for atrial fibrillation
- Atrial fibrillation, or AFib, is the most common heart rhythm disorder where the heart beats quickly and irregularly.
- AFib makes it difficult for the heart to pump blood and, therefore, increases a person's risk of certain heart diseases, stroke, and heart failure.
- Doctors may be able to treat AFib with medications or by attempting to reset the person's heart rate with electrical shocks.
- This article was reviewed by Jennifer Haythe, MD, Associate Professor of Medicine in the Division of Cardiology at Columbia University Medical Center.
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Atrial fibrillation, or AFib, is a condition in which the heart beats quickly and irregularly.
According to the Centers for Disease Control and Prevention, AFib is the most common heart rhythm disorder, and it's estimated to affect 2.7 million to 6.1 million Americans.
While brief heart rhythm variation can be common, the consistent irregularities associated with AFib can put certain individuals at increased risk of stroke and heart failure. Here's how to know if you have AFib and what you should do if you have it.
What AFib feels like
John Osborne, MD, a Dallas-based cardiologist, says that people with AFib usually notice their heart rate is elevated without a reason — like when they aren't exercising or stressed, which normally raises heart rate.
In fact, a heart in AFib can beat from 100 to 175 beats per minute (bpm), while the normal resting range for an adult is 60 to 100 bpm. You can test your pulse to see if it's abnormal, but a doctor should confirm your diagnosis with an electrocardiogram or other tests.
"Rather than the normal metronome of our heartbeat, which is pretty darn regular, you'll notice that it's irregular," Osborne says. It's sort of like "popcorn popping in the microwave."
According to the American Heart Association, patients have reported that AFib can feel like your heart skipped a beat, is fluttering, or "flip-flopping."
Other symptoms include fatigue, dizziness, shortness of breath, fainting, or confusion. If you're experiencing these symptoms and your resting heart rate seems abnormal, Osborne says it could be a medical emergency, and you should go to the hospital right away.
But in some cases, people don't notice any symptoms, and don't realize they have AFib. And according to Osborne, AFib isn't always a cause for concern. In certain otherwise low-risk individuals, Afib can be a nuisance but not dangerous.
"Heart rhythm issues — which are really ultimately an electrical issue — can be transient, by definition," Osborne says. "You may be electrically normal one moment, with a nice, regular pulse, and then the next moment be in AFib, or some other abnormal heart rhythm."
When AFib is considered dangerous
However, more permanent heart rhythm irregularities can be quite dangerous. AFib hinders the heart's ability to pump out blood, and as a result, blood can pool and form clots. Blood clots leading to the brain often cause strokes, so prolonged and untreated AFib can pose a serious risk.
In fact, research has found that AFib patients are three to five times more likely to have a stroke. About one-third of all strokes are caused by AFib, and such strokes are often more severe — causing worse impairment and potentially death — than in strokes where AFib isn't present.
AFib doesn't contribute to heart attack risk, but it is associated with the presence of other heart diseases, like congestive heart failure. The journal Circulation has reported that 13% to 27% of patients with heart failure also have AFib. How that connection works is still being researched — scientists don't know whether AFib leads to heart failure, or if the two conditions are simply correlated.
How to treat AFib
If you have AFib, a doctor may prescribe anticoagulants — or blood thinners — to reduce your risk of stroke. They may also try and reset your heart to its normal rate using electrical cardioversion, attaching patches to your chest and sending a small electric shock into your body.
A number of other treatments, like the medications Digoxin, Beta-blockers, and calcium channel blockers might also be prescribed. These procedures and medications don't "cure" AFib, however, and if the problem persists it might require surgery to normalize heart rate — such as catheter ablation, which involves scarring a small area of tissue in the heart that's causing AFib.
Osborne says that older people have a higher risk of developing AFib — about one in four people older than 40 will develop AFib as they age. That's because atrial tissue changes with age and the heart's conduction system is more likely to experience abnormalities.
Risk is also higher in people who have hypertension, or abnormally high blood pressure. According to the CDC, high blood pressure accounts for about one in five AFib cases. Conditions like sleep apnea and obesity can also contribute to the risk of AFib, Osborne says.
To reduce your risk of the dangerous conditions associated with AFib — like stroke or heart failure — you should exercise regularly, keep a heart-healthy diet, and reduce alcohol, caffeine, and tobacco use.
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