What is atrial fibrillation, and how do you know if you might have it?
When considering problems with the heart, you might first think of clogged arteries that lead to heart attacks. But the heart has an electrical system, which guides how it beats, that can separately go haywire. When that happens, the heart can’t pump in a rhythmic manner and blood flow to organs may be compromised. If this arrhythmia goes undetected or isn’t managed properly, it can cause strokes, heart failure and death.
The most common — and frequently undiagnosed — arrhythmia is atrial fibrillation, also known as AFib. An estimated 3 million to 6 million Americans have it, and studies show that the number will balloon to 12.1 million by 2030 as the population gets older. Recent studies also found that people who had COVID-19 have a higher risk of AFib and other heart diseases, even among those without a prior history of heart problems. And there is growing evidence that AFib significantly increases the risk of cognitive impairment and dementia. That is why it’s important to know the warning signs of atrial fibrillation and to get treatment early: It could save a person’s life.
What is atrial fibrillation?
Our hearts have four chambers. The two upper ones are the right and left atria, and the lower two are the ventricles. The heart’s electrical activity (via tissues that create electrical impulses) starts in the right atrium and spreads quickly to the left, allowing the atria to squeeze blood forward into the ventricles. Then, the electrical activity spreads to the ventricles, allowing them to contract and push blood to the rest of the body.
“Normally, the heart has a regular rhythm — like the ticking of a clock,” explained Dr. Geoffrey S. Pitt, a cardiologist at Weill Cornell Medicine and director of Cornell’s Cardiovascular Research Institute. “But when someone experiences AF, the irregular [electrical] activity causes the atria to quiver instead of maintaining coordinated pumping. The ventricles still continue to contract but lose their regular clocklike rhythm.”
Quivering of the atria and thwarted blood flow allow blood to pool and form clots in the upper heart chambers. These clots can then dislodge, travel through the bloodstream and obstruct other vessels, including those that supply the brain — causing strokes and sudden death. Studies show that strokes associated with atrial fibrillation can be more severe than strokes from other causes.
What does atrial fibrillation feel like?
Most commonly, patients feel palpitations, a sensation of racing heartbeats, shortness of breath, lightheadedness, weakness and fatigue, said Dr. Michael Honigberg, a cardiologist and researcher at Massachusetts General Hospital. Some people may also go on to experience heart failure and symptoms such as weight gain, difficulty breathing, and swelling in the belly and feet.
But some people may be completely asymptomatic. In fact, for 1 in 5 people who have a stroke associated with atrial fibrillation, the stroke is the first sign that they even have the condition. Otherwise, AFib might be incidentally discovered during a routine doctor visit.
When should you see a doctor?
People experiencing palpitations, shortness of breath, fatigue and lightheadedness should see a doctor, Dr. Pitt said. With the help of electrocardiograms and implanted devices such as loop recorders, physicians can then determine whether the palpitations are from atrial fibrillation or something else. These include generalized anxiety and panic disorder symptoms, medications such as decongestants and asthma inhalers, or overconsumption of substances like caffeine, nicotine and stimulant drugs.
Pay attention to AFib alerts from smart devices, which could provide warning signs to otherwise asymptomatic individuals. “The Apple Watch, Fitbit and AliveCor Kardia can monitor heart-rhythm irregularities and suggest a possible AF diagnosis, but it should be confirmed by a health care professional,” said Dr. Honigberg.
What might a doctor advise?
There are several treatment options depending on the extent of disease and stroke or bleeding risk, as well as how well patients can tolerate medications. “Treatment typically includes a blood thinner to protect against stroke, plus medication to control heart rate or maintain normal heart rhythm,” Dr. Honigberg said. If medications aren’t effective, doctors might advise catheter ablation or cardioversion. In an ablation, the tip of a catheter is used to destroy areas of heart tissue that are the source of irregular heartbeats. Cardioversion is done by sending shocks through electrodes placed over the chest that can quickly restore a normal heart rhythm.
An “under-discussed” part of managing AFib is lifestyle changes, said Dr. Honigberg: “Weight loss and alcohol moderation can be very helpful for reducing or preventing AF episodes.”
Dr. Honigberg also pointed out racial and ethnic disparities in AFib treatment and results. “Data consistently show that white individuals are more likely than other groups to undergo electrical cardioversion or an ablation procedure to prevent AF, and non-white individuals may have worse outcomes — for example, higher rates of stroke,” he said. Awareness of these disparities and advocating for care may make treatment more equitable.
What can increase the chances of atrial fibrillation?
Some conditions that contribute to atrial fibrillation are outside our control, while others we can potentially change. It is often associated with high blood pressure and congenital heart disease. One study found that AFib is the most common arrhythmia reported in people hospitalized with COVID-19, with 1 in 10 patients having developed it newly.
Traditional cardiovascular risk factors apply to AFib, including obesity, diabetes and smoking. Some studies show that people with diabetes have a 25% greater risk of developing the condition, and obesity increases the risk by nearly 50%. Alcohol consumption can also be a factor, with recent studies showing that even a single drink can raise the risk of having an AFib episode.