What is Atrial Fibrillation?

Introduction

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia (irregular heartbeat).^1–3 AF arises from cardiac remodeling, which leads to structural and electrical changes that then contribute to fibrillation, which are fast, irregular, unsynchronized muscle contractions, in the atria. Blood flows abnormally through the heart, thereby reducing the heart’s ability to pump blood and increasing the risk of blood clot. Triggers, such as atrial ischemia, inflammation, hemodynamic stress, alcohol or drug use, older age, neurological and endocrine disorders, or genetics, initiate AF.¹

Risk Factors, Symptoms, and Complications

There are various risk factors for AF, including older age, lower socioeconomic status, smoking, increased alcohol consumption, taller height, hypertension, cardiovascular disease (eg, heart failure, coronary artery disease), diabetes, and obstructive sleep apnea, among others.³ Symptoms of AF include chest pain, palpitations, decreased functional capacity, dyspnea (shortness of breath), and exercise intolerance.^1,2 Individuals with AF have an increased risk of heart failure, stroke, chronic kidney disease, peripheral artery disease, and cognitive impairment or dementia. AF also increases mortality risk, with women potentially having a greater mortality risk compared to men.³

Treatment

While AF is permanent, numerous treatment options are available that can help manage the condition to prevent further complications. Beta-blockers and calcium channel blockers are typically prescribed for rate control. When beta-blockers and calcium channel blockers are contraindicated, digoxin or amiodarone may be prescribed.^1–3 Patients with persistent rapid ventricular response despite pharmacologic therapy might receive atrioventricular nodal ablation (AVNA) via a pacemaker; AVNA is not recommended as a first-line treatment.³ Acute rhythm control treatments include electrical and pharmacological cardioversion. Electrical cardioversion restores sinus rhythm quickly and more effectively than pharmacologic cardioversion, and as such is recommended for hemodynamically unstable AF. Pharmacologic cardioversion is recommended for patients with hemodynamically stable AF or in cases where electrical cardioversion is contraindicated.³ Antiarrhythmic drugs (eg, flecainide, propafenone, dronedarone, amiodarone) are used for long-term rhythm control. Catheter ablation may be utilized in patients who cannot take antiarrhythmic drugs, or as a first-line treatment in select patients with symptomatic paroxysmal AF.^2,3

All patients with AF should be evaluated for the risk of thromboembolic events. Risk is commonly measured using the CHA₂DS₂-VASc, which assigns points to several risk factors (congestive heart failure, hypertension, age ≥75 years, diabetes, previous prior stroke/transient ischemic attack, vascular disease, age 65–74 years, and female sex);^2,3 a score of zero indicates low risk, a score of one indicates low-moderate risk, and a score of two or greater indicates moderate-high risk.¹ High-risk patients should receive oral anticoagulant therapy. Novel anticoagulants, which include dabigatran, rivaroxaban, apixaban, and edoxaban, are typically recommended over warfarin, except in cases of moderate-to-severe mitral stenosis or in patients with a mechanical heart valve. Oral anticoagulant use is reasonable in patients with low-moderate risk and is not necessary in patients with low risk.^1–3 For patients with a high-risk score in whom long-term anticoagulant use is contraindicated or with a high risk of bleeding on anticoagulant therapy, percutaneous left atrial appendage occlusion may be performed.³ 

Sources

1. Nesheiwat Z, Goyal A, Jagtap M. Atrial fibrillation. StatPearls. Updated 26 Apr 2023. Accessed 10 Oct 2025. 
2. Amin A, Houmsse A, Ishola A, Tyler J, Houmsse M. The current approach of atrial fibrillation management. Avicenna J Med. 2016;6(1):8–16. 
3. Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2024;149(1):e1–e156. Erratum in: Circulation. 2024;149(1):e167. Erratum in: Circulation. 2024;149(9):e936. Erratum in: Circulation. 2024;149(24):e1413.