Atrial fibrillation, often called AFib, is an irregular and often rapid heart rhythm. Some people feel it as fluttering or pounding. Others feel nothing at all and learn about it from a smartwatch alert or a routine EKG. Either way, it deserves attention, mainly because of its link to stroke.

What AFib is and how it feels

In AFib, the heart’s upper chambers quiver instead of squeezing in a steady rhythm, and the upper and lower chambers stop working together. The National Heart, Lung, and Blood Institute explains that blood can pool in the heart, which can lead to clots. AFib may come and go, or it may become permanent, and episodes often grow longer and more frequent over time.

The CDC lists these possible symptoms:

  • An irregular heartbeat or palpitations
  • Lightheadedness
  • Extreme fatigue
  • Shortness of breath
  • Chest pain

AFib becomes more common with age, and the CDC projects that about 12.1 million people in the United States will have it by 2050. Risk factors include high blood pressure, which accounts for about 1 in 5 cases, along with obesity, diabetes, heart failure, coronary disease, an overactive thyroid, chronic kidney disease, moderate to heavy drinking and smoking.

Should people without symptoms be screened? The U.S. Preventive Services Task Force concluded in 2022 that there is not enough evidence to recommend for or against routine screening for AFib. In practice, an irregular pulse found at a checkup, or an alert from a wearable device, is followed up with an EKG.

Why stroke is the main concern

Clots that form in the quivering upper chamber can travel to the brain. According to the CDC, AFib is linked to roughly a fivefold higher risk of ischemic stroke, causes about 1 in 7 strokes, and strokes caused by AFib tend to be more severe.

The 2023 guideline on AFib from the American College of Cardiology, the American Heart Association and two other societies asks clinicians to estimate each person’s stroke risk with a validated score such as CHA2DS2-VASc, which counts factors like age, sex, high blood pressure, diabetes, heart failure and prior stroke. The ACC’s summary of that guideline notes that for people whose yearly stroke risk is about 2 percent or higher, stroke prevention should be based on that risk, whether the AFib comes and goes or is constant.

Treatment: three parts that work together

Preventing stroke. For most people who need a blood thinner, the guideline prefers the newer direct oral anticoagulants over warfarin, except in people with mitral stenosis or a mechanical heart valve. Aspirin alone is not recommended as a substitute. Bleeding risk is weighed, but a bleeding score alone should not decide whether someone gets a blood thinner. For people who cannot take blood thinners long term, a device that closes off the left atrial appendage, a small pouch of the upper chamber, is now given stronger support.

Controlling rate and rhythm. Medicines can slow the heart or help hold a normal rhythm. Catheter ablation, a procedure that targets the tissue setting off AFib, is now recommended as a first option for selected patients, according to the 2023 guideline, and for suitable patients with heart failure and a weak heart muscle.

Treating the causes. The guideline calls lifestyle and risk factor changes a pillar of AFib care: losing weight when needed, regular exercise, quitting tobacco, limiting alcohol, controlling blood pressure, and screening for sleep apnea. These can reduce how often AFib returns. Our articles on sleep apnea and the heart and alcohol after 50 go further.

When to call, and when to call 911

Call your doctor soon if you notice a new irregular pulse, a smartwatch alert you cannot explain, or palpitations that keep coming back. Call 911 for chest pain, fainting or severe shortness of breath, or for any stroke warning sign. The CDC’s B.E. F.A.S.T. check is: Balance loss, Eye or vision changes, Face drooping, Arm drifting down, Speech slurred or strange, Time to call 911. Do not drive yourself to the hospital.

People with AFib usually see a cardiologist, and day-to-day care still depends on someone keeping the whole picture straight: blood pressure, kidney function, which affects blood thinner dosing, and every medicine on the list. Dr. Shtern coordinates that care with specialists, as described on our specialists and hospital care and hypertension pages. If you would like to meet her first, the first visit is a complimentary meet and greet.

This article is general information, not advice for your situation. Members can call the office with questions about their own care.