Atrial fibrillation

Atrial fibrillation (AFib) is the most common sustained heart-rhythm disorder. In AFib the upper chambers of the heart (the atria) beat irregularly and often rapidly, out of coordination with the lower chambers (the ventricles). This inefficient pumping can allow blood to pool in the atria and form clots, which may travel to the brain and cause a stroke.

AFib may be occasional (paroxysmal), persistent, or permanent. Some people feel rapid or irregular heartbeats; others have no symptoms and discover the condition only when a stroke or other complication occurs. Treatment focuses on preventing stroke, controlling heart rate or restoring normal rhythm, and managing underlying conditions. With proper care most people with AFib live full lives.

Symptoms of atrial fibrillation can include:

• Palpitations — sensations of a racing, uncomfortable, irregular heartbeat or a flipping in the chest
• Weakness or fatigue
• Reduced ability to exercise
• Lightheadedness or dizziness
• Shortness of breath
• Chest pain or pressure
• Confusion (in some older adults)

Some people have no symptoms at all. The severity of symptoms does not always correlate with the risk of stroke; even asymptomatic AFib carries elevated stroke risk and usually requires anticoagulation assessment.

Atrial fibrillation occurs when the heart’s electrical signals become chaotic in the atria. Instead of the sinus node directing an orderly contraction, many different impulses fire rapidly and irregularly. Common contributing factors include:

• High blood pressure (the most common associated condition)
• Coronary artery disease or prior heart attack
• Heart-valve disease
• Heart failure or cardiomyopathy
• Congenital heart defects
• Overactive thyroid
• Obesity and sleep apnea
• Diabetes
• Chronic lung disease
• Excessive alcohol use or acute illness (“holiday heart”)
• Advancing age

In some people no clear structural heart disease is found (lone atrial fibrillation).

Risk factors for developing atrial fibrillation include:

• Increasing age (risk rises sharply after 60)
• High blood pressure
• Obesity
• Sleep apnea
• Diabetes
• Heart disease of any kind
• Family history of AFib
• European ancestry (higher reported rates)
• Excessive alcohol consumption
• Smoking
• Endurance athletic activity (in some studies)

The most important complication is ischemic stroke. Because blood can pool in the fibrillating atria, clots may form (especially in the left atrial appendage) and travel to the brain. AFib is responsible for about one in seven strokes and tends to cause more severe strokes than other causes.

Other complications include:

• Heart failure — the inefficient rhythm can weaken the heart over time
• Chronic fatigue and reduced exercise capacity
• Cognitive impairment and higher risk of dementia
• Reduced quality of life

While not all AFib can be prevented, the following measures reduce risk and improve outcomes:

• Control blood pressure and treat sleep apnea
• Maintain a healthy weight
• Exercise regularly but avoid extreme endurance overtraining if at risk
• Limit alcohol and do not smoke
• Manage cholesterol and diabetes
• Treat underlying heart disease

For people who already have AFib, the most critical preventive step is appropriate anticoagulation to reduce stroke risk.

Atrial fibrillation is diagnosed with an electrocardiogram (ECG) that shows the characteristic irregular rhythm without distinct P waves. Because AFib can come and go, longer-term monitoring is often needed:

• Holter monitor (24–48 hours)
• Event monitor or mobile cardiac telemetry (weeks)
• Implantable loop recorder (months to years)
• Smartwatch or consumer ECG devices that can capture episodes

Additional tests evaluate the heart’s structure and function (echocardiogram), look for coronary disease, check thyroid function, and assess stroke risk (CHA₂DS₂-VASc score) and bleeding risk.

See a doctor if you notice a rapid, irregular pulse, unexplained fatigue, shortness of breath, or episodes of palpitations. Seek emergency care for chest pain, severe shortness of breath, fainting, or signs of stroke (sudden numbness, confusion, trouble speaking or seeing).

People with known AFib should contact their clinician if symptoms worsen or if they experience bleeding while on anticoagulant medicine.

Treatment has three main goals: prevent stroke, control heart rate, and restore or maintain normal rhythm when appropriate.

Stroke prevention
Most people with AFib and additional stroke risk factors need long-term oral anticoagulation (warfarin or direct oral anticoagulants such as apixaban, rivaroxaban, edoxaban, or dabigatran). Left atrial appendage closure devices are an option for selected patients who cannot take long-term anticoagulants.

Rate control
Medicines (beta-blockers, calcium-channel blockers, digoxin) slow the ventricular rate so the heart can pump more effectively.

Rhythm control

• Antiarrhythmic medicines
• Electrical cardioversion
• Catheter ablation (pulmonary-vein isolation) — increasingly used as first-line therapy in selected patients
• Surgical ablation (maze procedure) in patients undergoing heart surgery for other reasons

The choice between rate and rhythm control is individualized based on symptoms, age, heart function, and patient preference.

Living well with atrial fibrillation includes:

• Taking anticoagulant and other heart medicines exactly as prescribed
• Knowing the signs of stroke and bleeding and seeking help immediately
• Monitoring pulse or using a home ECG device if recommended
• Maintaining a healthy weight, exercising as advised, and limiting alcohol
• Treating sleep apnea if present
• Keeping all follow-up appointments and lab tests (especially if on warfarin)
• Carrying a list of medicines and the diagnosis of AFib in case of emergency

Helpful information to bring includes:

• Description of symptoms and how often they occur
• List of all medicines and supplements
• Personal and family history of heart disease, stroke, or bleeding problems
• Results of previous ECGs or heart monitors
• Questions about stroke risk, anticoagulation options, rate versus rhythm control, and whether ablation might be appropriate

If you have a smartwatch or home ECG recordings of episodes, bring those data as well.