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Overview

What Is Atrial Fibrillation?

Atrial fibrillation is an irregular, often rapid heartbeat caused by disorganized electrical signals in the heart’s upper chambers, called the atria. Instead of contracting in a coordinated rhythm, the atria quiver, which can affect how efficiently blood moves through the heart. Atrial fibrillation may occur in episodes that stop on their own or persist for longer periods. It can affect adults of many ages, but it is more common in older adults and people with cardiovascular conditions.

Symptoms

Atrial Fibrillation Symptoms

Atrial fibrillation symptoms may begin suddenly and may come and go, especially with paroxysmal atrial fibrillation. Some people have no noticeable symptoms even when their heart rhythm is abnormal, so an irregular pulse may be found during a routine check.

  • Palpitations
  • A fast or irregular pulse
  • Fatigue
  • Shortness of breath
  • Dizziness
  • Lightheadedness
  • Reduced ability to exercise
  • Chest discomfort

ACT PROMPTLY

Some symptoms need urgent care

Seek emergency medical attention for sudden chest pain, severe breathing difficulty, fainting, or possible stroke symptoms. Do not wait for a routine appointment when these symptoms occur.

Causes

Causes of Atrial Fibrillation

Atrial fibrillation occurs when abnormal electrical signals cause the atria to quiver instead of contracting in a coordinated rhythm. Changes in the heart’s structure, underlying health conditions, or temporary stress on the body may contribute. Sometimes, no single cause can be found.

  • High blood pressure can place ongoing strain on the heart and its electrical system.
  • Coronary artery disease or a prior heart attack can damage heart tissue and affect rhythm.
  • Heart valve disease can stretch or change the structure of the atria.
  • Heart failure can alter pressure and electrical signaling in the heart.
  • Thyroid disease, especially an overactive thyroid, may trigger an abnormal rhythm.
  • Sleep apnea can repeatedly stress the heart during pauses in breathing.
  • Alcohol use, particularly heavy or binge drinking, can trigger episodes in some people.
  • Severe illness can temporarily place stress on the heart and contribute to fibrillation.
  • Cardiothoracic surgery may temporarily disrupt the heart’s rhythm.

Risk Factors

Risk Factors for Atrial Fibrillation

CANNOT CHANGE

Increasing age, a family history of atrial fibrillation, and prior cardiovascular disease can increase risk but cannot be changed.

MAY BE MODIFIED

High blood pressure, obesity, diabetes, smoking, heavy alcohol use, and untreated sleep apnea may be reduced or treated with medical and lifestyle support.

Having one or more risk factors does not guarantee that atrial fibrillation will develop. Addressing modifiable risks can support treatment, lower the chance of complications, and improve overall cardiovascular health.

Complications

Complications of Atrial Fibrillation

  • Blood clots may form when blood does not move normally through the atria.
  • An ischemic stroke can occur if a clot travels to and blocks blood flow in the brain.
  • Heart failure may develop or worsen when the heart is strained over time.
  • Worsening heart function can reduce the heart’s ability to pump effectively.
  • Symptoms and ongoing care needs may reduce quality of life.
  • Other cardiovascular diseases may become more difficult to manage or may cause additional complications.

WHY TREATMENT MATTERS

Atrial fibrillation can raise stroke risk

Stroke risk varies according to individual factors such as age, other medical conditions, and previous events. After assessing the balance of benefits and bleeding risks, clinicians may recommend blood-thinning medication to help prevent clots.

Diagnosis

How Atrial Fibrillation Is Diagnosed

Diagnosis starts with a medical history, a review of symptoms and pulse, and a physical examination. An electrocardiogram, or ECG, is the main test used to document atrial fibrillation and assess the heart’s rhythm. Because episodes may come and go, additional testing may be needed.

  • Holter or event monitoring records the heart rhythm over a longer period to detect intermittent episodes.
  • Echocardiography uses ultrasound to assess the heart’s structure and pumping function.
  • Blood tests can check for thyroid disease and other contributors to an abnormal rhythm.
  • Additional testing may be used when another heart or lung problem is suspected.

Treatment & Management

Atrial Fibrillation Treatment and Management

REDUCE STROKE RISK

Anticoagulants may be recommended based on a person’s individual risk of stroke and bleeding.

CONTROL RATE OR RHYTHM

Medicines and procedures can slow the heart rate or help restore and maintain a more regular rhythm.

  • Anticoagulants help reduce the formation of blood clots when prescribed for stroke prevention.
  • Rate-control medicines slow the heart rate so the ventricles do not beat too quickly.
  • Rhythm-control medicines help restore or maintain a more regular heart rhythm.
  • Electrical cardioversion uses a controlled electrical impulse to restore a regular rhythm.
  • Catheter ablation treats areas that produce abnormal electrical signals and may reduce episodes.
  • Treating contributing conditions, such as high blood pressure or sleep apnea, can support rhythm and cardiovascular health.

Atrial fibrillation treatment depends on its type and duration, symptoms, stroke risk, heart structure, other health conditions, medication risks, and personal preferences. Long-term follow-up helps clinicians adjust care over time. Lifestyle measures may include limiting excess alcohol, not smoking, being physically active as advised, and managing weight and blood pressure.

Prevention

Preventing Atrial Fibrillation and Its Complications

  • Control blood pressure with monitoring, lifestyle measures, and prescribed treatment.
  • Manage diabetes and cholesterol as part of an overall cardiovascular care plan.
  • Maintain a healthy weight with sustainable nutrition and activity habits.
  • Avoid tobacco and ask a clinician for help stopping if needed.
  • Limit alcohol, especially if it triggers palpitations or episodes.
  • Treat sleep apnea and use prescribed therapy consistently.
  • Stay physically active as advised by a healthcare professional.
  • Take prescribed anticoagulants or other medicines correctly and do not stop them without medical advice.

Outlook and Prognosis

Outlook and Prognosis for Atrial Fibrillation

Atrial fibrillation may be intermittent, persistent, or long-standing. Some people maintain a normal rhythm after treatment, while others need ongoing management rather than a permanent cure. With regular care, many people manage the condition while focusing on symptom control and reducing stroke risk.

  • A person’s stroke-risk profile helps determine the need for preventive treatment.
  • Underlying heart disease can affect symptoms, treatment choices, and long-term outlook.
  • The number and severity of symptoms influence quality of life and management needs.
  • Response to medicines or ablation can shape whether episodes continue or recur.
  • Control of modifiable risks may reduce complications and support better heart health.
  • Regular follow-up allows clinicians to monitor the rhythm, medicines, and heart function.

When Should You See a Doctor

When Should You See a Doctor?

EMERGENCY WARNING

Call emergency services immediately

Call emergency services for chest pain, severe breathing difficulty, or fainting. Also seek immediate help for possible stroke signs, including facial drooping, arm weakness, speech difficulty, sudden confusion, or sudden vision or balance changes.

If you have diagnosed atrial fibrillation, keep follow-up appointments and report bleeding or medication problems to your healthcare team. Seek urgent medical advice for symptoms that are sustained, worsening, or different from your usual episodes.

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