Atrial fibrillation#Electrophysiology

File:Atrial fib stroke.jpg

Atrial fibrillation is usually accompanied by symptoms related to a rapid heart rate. Rapid and irregular heart rates may be perceived as the sensation of the heart beating too fast, irregularly, or skipping beats (palpitations) or exercise intolerance.

Other possible symptoms include congestive heart failure symptoms such as fatigue, shortness of breath, or swelling. Loss of consciousness can also occur on atrial fibrillations due to lack of oxygen and blood to the brain. The abnormal heart rhythm (arrhythmia) is sometimes only identified with the onset of a stroke or a transient ischemic attack (TIA). It is not uncommon for a person to first become aware of AF from a routine physical examination or electrocardiogram, as it often does not cause symptoms.

Since most cases of AF are secondary to other medical problems, the presence of chest pain or angina, signs and symptoms of hyperthyroidism (an overactive thyroid gland) such as weight loss and diarrhea, and symptoms suggestive of lung disease can indicate an underlying cause. A history of stroke or TIA, as well as high blood pressure, diabetes, heart failure, or rheumatic fever, may indicate whether someone with AF is at a higher risk of complications.

Presentation is similar to other forms of rapid heart rate and may be asymptomatic. Palpitations and chest discomfort are common complaints. The rapid uncoordinated heart rate may result in reduced output of blood pumped by the heart (cardiac output), resulting in inadequate blood flow, and therefore oxygen delivery to the rest of the body. Common symptoms of uncontrolled atrial fibrillation may include shortness of breath, shortness of breath when lying flat, dizziness, and sudden onset of shortness of breath during the night. This may progress to swelling of the lower extremities, a manifestation of congestive heart failure. Due to inadequate cardiac output, individuals with AF may also complain of lightheadedness.{{cite journal | vauthors = Gutierrez C, Blanchard DG | title = Atrial fibrillation: diagnosis and treatment | journal = American Family Physician | volume = 83 | issue = 1 | pages = 61–68 | date = January 2011 | pmid = 21888129 | url = http://www.aafp.org/afp/2011/0101/p61.html | url-status = live | type = Review | archive-url = https://web.archive.org/web/20131224120005/http://www.aafp.org/afp/2011/0101/p61.html | archive-date = 24 December 2013 }}

AF can cause respiratory distress due to congestion in the lungs. By definition, the heart rate will be greater than 100 beats per minute. Blood pressure may be variable, and often difficult to measure as the beat-by-beat variability causes problems for most digital (oscillometric) non-invasive blood pressure monitors. For this reason, when determining the heart rate in AF, direct cardiac auscultation is recommended. Low blood pressure is most concerning, and a sign that immediate treatment is required. Many of the symptoms associated with uncontrolled atrial fibrillation are a manifestation of congestive heart failure due to the reduced cardiac output. The affected person's respiratory rate often increases in the presence of respiratory distress. Pulse oximetry may confirm the presence of too little oxygen reaching the body's tissues, related to any precipitating factors such as pneumonia. Examination of the jugular veins may reveal elevated pressure (jugular venous distention). Examination of the lungs may reveal crackles, which are suggestive of pulmonary edema. Examination of the heart will reveal a rapid irregular rhythm.{{citation needed|date=September 2022}}

File:RiskFactors.jpg (top left box) and modifiable risk factors (bottom left box) for atrial fibrillation. The main outcomes of atrial fibrillation are in the right box. BMI=Body Mass Index.]]

AF is linked to several forms of cardiovascular disease but may occur in otherwise normal hearts. Cardiovascular factors known to be associated with the development of AF include high blood pressure,{{cite journal | vauthors = Kim SH, Lim KR, Chun KJ | title=Higher heart rate variability as a predictor of atrial fibrillation in patients with hypertensione | journal= Scientific Reports | volume=12 | issue=1 | page=3702 | year=2022 | doi= 10.1038/s41598-022-07783-3 | pmc=8904557 | pmid=35260686 | bibcode=2022NatSR..12.3702K }} coronary artery disease, mitral valve stenosis (e.g., due to rheumatic heart disease or mitral valve prolapse), mitral regurgitation, left atrial enlargement, hypertrophic cardiomyopathy, pericarditis, congenital heart disease, and previous heart surgery.{{cite journal | vauthors = Marelli A, Miller SP, Marino BS, Jefferson AL, Newburger JW | title = Brain in Congenital Heart Disease Across the Lifespan: The Cumulative Burden of Injury | journal = Circulation | volume = 133 | issue = 20 | pages = 1951–1962 | date = May 2016 | pmid = 27185022 | pmc = 5519142 | doi = 10.1161/CIRCULATIONAHA.115.019881 }} People with congenital heart disease tend to develop atrial fibrillation at a younger age, that is more likely to be of right atrial origin (atypical) than of left origin, and have a greater risk of progressing to permanent atrial fibrillation.{{cite journal | vauthors = Ebrahim MA, Escudero CA, Kantoch MJ, Vondermuhll IF, Atallah J | title = Insights on Atrial Fibrillation in Congenital Heart Disease | journal = The Canadian Journal of Cardiology | volume = 34 | issue = 11 | pages = 1531–1533 | date = November 2018 | pmid = 30404756 | doi = 10.1016/j.cjca.2018.08.010 | s2cid = 53213100 }}

Additionally, lung diseases (such as pneumonia, lung cancer, pulmonary embolism, and sarcoidosis) may play a role in certain people. Sepsis also increases the risk of developing new-onset atrial fibrillation.{{cite journal | vauthors = Kuipers S, Klein Klouwenberg PM, Cremer OL | title = Incidence, risk factors and outcomes of new-onset atrial fibrillation in patients with sepsis: a systematic review | journal = Critical Care | volume = 18 | issue = 6 | page = 688 | date = December 2014 | pmid = 25498795 | pmc = 4296551 | doi = 10.1186/s13054-014-0688-5 | type = Systematic Review | doi-access = free }}{{cite journal | vauthors = Walkey AJ, Hogarth DK, Lip GY | title = Optimizing atrial fibrillation management: from ICU and beyond | journal = Chest | volume = 148 | issue = 4 | pages = 859–864 | date = October 2015 | pmid = 25951122 | pmc = 4594627 | doi = 10.1378/chest.15-0358 | type = Review }} Disorders of breathing during sleep, such as obstructive sleep apnea (OSA), are also associated with AF.{{cite journal | vauthors = Abed HS, Wittert GA | title = Obesity and atrial fibrillation | journal = Obesity Reviews | volume = 14 | issue = 11 | pages = 929–938 | date = November 2013 | pmid = 23879190 | doi = 10.1111/obr.12056 | s2cid = 25479450 }}{{cite journal | vauthors = Hoyer FF, Lickfett LM, Mittmann-Braun E, Ruland C, Kreuz J, Pabst S, Schrickel J, Juergens U, Tasci S, Nickenig G, Skowasch D | title = High prevalence of obstructive sleep apnea in patients with resistant paroxysmal atrial fibrillation after pulmonary vein isolation | journal = Journal of Interventional Cardiac Electrophysiology | volume = 29 | issue = 1 | pages = 37–41 | date = October 2010 | pmid = 20714922 | doi = 10.1007/s10840-010-9502-8 | s2cid = 11129249 }} OSA, specifically, was found to be a very strong predictor of atrial fibrillation. Patients with OSA were shown to have an increased incidence of atrial fibrillation and a study done by Gami et al. demonstrated that increased nocturnal oxygen desaturation from OSA severity was correlated with higher incidences of atrial fibrillation.{{cite journal | vauthors = Gami AS, Hodge DO, Herges RM, Olson EJ, Nykodym J, Kara T, Somers VK | title = Obstructive sleep apnea, obesity, and the risk of incident atrial fibrillation | journal = Journal of the American College of Cardiology | volume = 49 | issue = 5 | pages = 565–571 | date = February 2007 | pmid = 17276180 | doi = 10.1016/j.jacc.2006.08.060 }} Obesity is a risk factor for AF.{{cite journal | vauthors = Magnani JW, Hylek EM, Apovian CM | title = Obesity begets atrial fibrillation: a contemporary summary | journal = Circulation | volume = 128 | issue = 4 | pages = 401–405 | date = July 2013 | pmid = 23877062 | pmc = 3866045 | doi = 10.1161/CIRCULATIONAHA.113.001840 }} Hyperthyroidism and subclinical hyperthyroidism are associated with AF development.{{cite journal | vauthors = Palmeiro C, Davila MI, Bhat M, Frishman WH, Weiss IA | title = Subclinical hyperthyroidism and cardiovascular risk: recommendations for treatment | journal = Cardiology in Review | volume = 21 | issue = 6 | pages = 300–308 | date = December 2013 | pmid = 23563523 | doi = 10.1097/CRD.0b013e318294f6f1 | s2cid = 2311111 }}

Caffeine consumption does not appear to be associated with AF;{{cite journal | vauthors = Cheng M, Hu Z, Lu X, Huang J, Gu D | title = Caffeine intake and atrial fibrillation incidence: dose response meta-analysis of prospective cohort studies | journal = The Canadian Journal of Cardiology | volume = 30 | issue = 4 | pages = 448–454 | date = April 2014 | pmid = 24680173 | doi = 10.1016/j.cjca.2013.12.026 }} excessive alcohol consumption ("binge drinking" or "holiday heart syndrome") is linked to AF.{{cite journal | vauthors = Voskoboinik A, Prabhu S, Ling LH, Kalman JM, Kistler PM | title = Alcohol and Atrial Fibrillation: A Sobering Review | journal = Journal of the American College of Cardiology | volume = 68 | issue = 23 | pages = 2567–2576 | date = December 2016 | pmid = 27931615 | doi = 10.1016/j.jacc.2016.08.074 | doi-access = free }} Low-to-moderate alcohol consumption also appears to be associated with an increased risk of developing atrial fibrillation, although the increase in risk associated with drinking less than two drinks daily appears to be small. Tobacco smoking and secondhand tobacco smoke exposure are associated with an increased risk of developing atrial fibrillation.{{cite journal | vauthors = Staerk L, Sherer JA, Ko D, Benjamin EJ, Helm RH | title = Atrial Fibrillation: Epidemiology, Pathophysiology, and Clinical Outcomes | journal = Circulation Research | volume = 120 | issue = 9 | pages = 1501–1517 | date = April 2017 | pmid = 28450367 | pmc = 5500874 | doi = 10.1161/CIRCRESAHA.117.309732 | type = Review }}{{cite journal | vauthors = Du X, Dong J, Ma C | title = Is Atrial Fibrillation a Preventable Disease? | journal = Journal of the American College of Cardiology | volume = 69 | issue = 15 | pages = 1968–1982 | date = April 2017 | pmid = 28408027 | doi = 10.1016/j.jacc.2017.02.020 | type = Review | doi-access = free }} Long-term endurance exercise that far exceeds the recommended amount of exercise (e.g., long-distance cycling or marathon running) appears to be associated with a modest increase in the risk of atrial fibrillation in middle-aged and elderly people.{{cite journal | vauthors = Wilhelm M | title = Atrial fibrillation in endurance athletes | journal = European Journal of Preventive Cardiology | volume = 21 | issue = 8 | pages = 1040–1048 | date = August 2014 | pmid = 23610454 | doi = 10.1177/2047487313476414 | s2cid = 22065631 | doi-access = free }}{{cite journal | vauthors = Elliott AD, Mahajan R, Pathak RK, Lau DH, Sanders P | title = Exercise Training and Atrial Fibrillation: Further Evidence for the Importance of Lifestyle Change | journal = Circulation | volume = 133 | issue = 5 | pages = 457–459 | date = February 2016 | pmid = 26733608 | doi = 10.1161/CIRCULATIONAHA.115.020800 | s2cid = 2475456 }}

Major stress biomarkers (including cortisol and heat shock proteins) indicate that stress plays a significant role in causing atrial fibrillation.{{cite journal | vauthors = Rafaqat S, Rafaqat S, Rafaqat S | title = The Role of Major Biomarkers of Stress in Atrial Fibrillation: A Literature Review | journal = The Journal of Innovations in Cardiac Rhythm Management | volume = 14 | issue = 2 | pages = 5355–5364 | date = February 2023 | pmid = 36874560 | pmc = 9983621 | doi = 10.19102/icrm.2023.14025 }} There is some evidence that night shift working may be linked to a diagnosis of AF.{{cite web |title=Night shift work is linked to increased risk of heart problems |url=https://www.escardio.org/The-ESC/Press-Office/Press-releases/Night-shift-work-is-linked-to-increased-risk-of-heart-problems |website=Escardio |access-date=16 August 2021}}

Atrial fibrillation is associated with elevated levels of inflammatory markers and clotting factors.{{cite journal | vauthors=Hazarapetyan L, Zelveian PH, Grigoryan S | title=Inflammation and Coagulation are Two Interconnected Pathophysiological Pathways in Atrial Fibrillation Pathogenesis | journal=Journal of Inflammation Research | volume=16 | pages=4967–4975 | year=2023 | doi = 10.2147/JIR.S429892 | doi-access=free | pmc=10625332 | pmid=37927962 }} Mendelian randomization indicates a causal relationship of inflammation leading to atrial fibrillation.{{cite journal | vauthors=Chu H, Guo X, Wang Y | title=Causal relationship between immune cells and atrial fibrillation: A Mendelian randomization study | journal=Medicine | volume=103 | issue=19 | pages=e38079 | year=2024 | doi = 10.1097/MD.0000000000038079 | pmc=11081550 | pmid=38728471 }}

Family history in a first degree relative is associated with a 40% increase in risk of AF. This finding led to the mapping of different loci such as 10q22-24, 6q14-16 and 11p15-5.3 and discover mutations associated with the loci. Mutations have been found in the genes of K⁺ channels and Na⁺ channels which affect the processes of polarization-depolarization of the myocardium, cellular hyper-excitability, shortening of effective refractory period favoring re-entries.

Using genome-wide association study (GWAS), which screen the entire genome for single nucleotide polymorphism (SNP), three susceptibility loci have been found for AF (4q25, 1q21 and 16q22).{{cite journal | vauthors = Shoemaker MB, Bollmann A, Lubitz SA, Ueberham L, Saini H, Montgomery J, Edwards T, Yoneda Z, Sinner MF, Arya A, Sommer P, Delaney J, Goyal SK, Saavedra P, Kanagasundram A, Whalen SP, Roden DM, Hindricks G, Ellis CR, Ellinor PT, Darbar D, Husser D | title = Common genetic variants and response to atrial fibrillation ablation | journal = Circulation: Arrhythmia and Electrophysiology | volume = 8 | issue = 2 | pages = 296–302 | date = April 2015 | pmid = 25684755 | pmc = 4731871 | doi = 10.1161/CIRCEP.114.001909 }} In these loci there are SNPs associated with a 30% increase in risk of recurrent atrial tachycardia after ablation. There are also SNPs associated with loss of function of the Pitx2c gene (involved in cellular development of pulmonary valves), responsible for re-entries. There are also SNPs close to ZFHX3 genes involved in the regulation of Ca²⁺. A 2018 meta-analysis of GWAS studies identified 97 locis associated with AF, of which 70 were newly identified associations: they are associated with genes that encode transcription factors, such as TBX3 and TBX5, NKX2-5 or PITX2, involved in the regulation of cardiac conduction, modulation of ion channels and in cardiac development.{{cite journal | vauthors = Roselli C, Chaffin MD, Weng LC, Aeschbacher S, Ahlberg G, Albert CM, Almgren P, Alonso A, Anderson CD, Aragam KG, Arking DE | title = Multi-ethnic genome-wide association study for atrial fibrillation | journal = Nature Genetics | volume = 50 | issue = 9 | pages = 1225–1233 | date = June 2018 | pmid = 29892015 | pmc = 6136836 | doi = 10.1038/s41588-018-0133-9 }}

A sedentary lifestyle increases the risk factors associated with AF, such as obesity, hypertension, or diabetes mellitus. This favors remodeling processes of the atrium due to inflammation or alterations in the depolarization of cardiomyocytes by elevation of sympathetic nervous system activity.{{cite journal | vauthors = Thorp AA, Owen N, Neuhaus M, Dunstan DW | title = Sedentary behaviors and subsequent health outcomes in adults a systematic review of longitudinal studies, 1996-2011 | journal = American Journal of Preventive Medicine | volume = 41 | issue = 2 | pages = 207–215 | date = August 2011 | pmid = 21767729 | doi = 10.1016/j.amepre.2011.05.004 }} A sedentary lifestyle is associated with an increased risk of AF compared to physical activity. In both men and women, the practice of moderate exercise reduces the risk of AF progressively;{{cite journal | vauthors = Mohanty S, Mohanty P, Tamaki M, Natale V, Gianni C, Trivedi C, Gokoglan Y, DI Biase L, Natale A | title = Differential Association of Exercise Intensity With Risk of Atrial Fibrillation in Men and Women: Evidence from a Meta-Analysis | journal = Journal of Cardiovascular Electrophysiology | volume = 27 | issue = 9 | pages = 1021–1029 | date = September 2016 | pmid = 27245609 | doi = 10.1111/jce.13023 | s2cid = 206025944 }} intense sports may increase the risk of developing AF, as seen in athletes.{{cite journal | vauthors = Abdulla J, Nielsen JR | title = Is the risk of atrial fibrillation higher in athletes than in the general population? A systematic review and meta-analysis | journal = Europace | volume = 11 | issue = 9 | pages = 1156–1159 | date = September 2009 | pmid = 19633305 | doi = 10.1093/europace/eup197 | doi-access = free }} It is due to a remodeling of cardiac tissue,{{cite journal | vauthors = D'Andrea A, Riegler L, Cocchia R, Scarafile R, Salerno G, Gravino R, Golia E, Vriz O, Citro R, Limongelli G, Calabrò P, Di Salvo G, Caso P, Russo MG, Bossone E, Calabrò R | title = Left atrial volume index in highly trained athletes | journal = American Heart Journal | volume = 159 | issue = 6 | pages = 1155–1161 | date = June 2010 | pmid = 20569734 | doi = 10.1016/j.ahj.2010.03.036 }} and an increase in vagal tone, which shortens the effective refractory period (ERP) favoring re-entries from the pulmonary veins.

The rate of AF in smokers is 1.4 times higher than in non-smokers. Snus consumption, which delivers nicotine at a dose equivalent to that of cigarettes, is not correlated with AF.{{cite journal | vauthors = Hergens MP, Galanti R, Hansson J, Fredlund P, Ahlbom A, Alfredsson L, Bellocco R, Eriksson M, Fransson EI, Hallqvist J, Jansson JH, Knutsson A, Pedersen N, Lagerros YT, Ostergren PO, Magnusson C | title = Use of Scandinavian moist smokeless tobacco (snus) and the risk of atrial fibrillation | journal = Epidemiology | volume = 25 | issue = 6 | pages = 872–876 | date = November 2014 | pmid = 25166877 | doi = 10.1097/EDE.0000000000000169 | s2cid = 24080017 | doi-access = free }}

Acute alcohol consumption can directly trigger an episode of atrial fibrillation. Regular alcohol consumption also increases the risk of atrial fibrillation in several ways. The long-term use of alcohol alters the physical structure and electrical properties of the atria. Alcohol consumption does this by repeatedly stimulating the sympathetic nervous system, increasing inflammation in the atria, raising blood pressure, lowering the levels of potassium and magnesium in the blood, worsening obstructive sleep apnea, and by promoting harmful structural changes (remodeling) in the atria and ventricles of the heart. This remodeling leads to abnormally increased pressure in the left atrium, inappropriately dilates it, and increases scarring (fibrosis) in the left atrium. The aforementioned structural changes increase the risk of developing atrial fibrillation when paired with the harmful changes in how the left atrium conducts electricity.

Hypertension is reportedly present in 49% to 90% of patients with atrial fibrillation.Manolis AJ, Rosei EA, Coca A, Cifkova R, Erdine SE, Kjeldsen S, Lip GY, Narkiewicz K, Parati G, Redon J, Schmieder R, Tsioufis C, Mancia G. Hypertension and atrial fibrillation: diagnostic approach, prevention and treatment. Position paper of the Working Group 'Hypertension Arrhythmias and Thrombosis' of the European Society of Hypertension. J Hypertens. 2012 Feb;30(2):239-52. doi: 10.1097/HJH.0b013e32834f03bf. PMID: 22186358. Available online at: https://www.eshonline.org/esh-content/uploads/2015/02/posistion_esh_af_2012.pdf According to the CHARGE Consortium, both systolic and diastolic blood pressure are predictors of the risk of AF. Systolic blood pressure values close to normal limit the increase in the risk associated with AF. Diastolic dysfunction is also associated with AF, which increases left atrial pressure, left atrial volume, size, and left ventricular hypertrophy, characteristic of chronic hypertension. All atrial remodeling is related to heterogeneous conduction and the formation of re-entrant electric conduction from the pulmonary veins.{{cite journal | vauthors = Alonso A, Krijthe BP, Aspelund T, Stepas KA, Pencina MJ, Moser CB, Sinner MF, Sotoodehnia N, Fontes JD, Janssens AC, Kronmal RA, Magnani JW, Witteman JC, Chamberlain AM, Lubitz SA, Schnabel RB, Agarwal SK, McManus DD, Ellinor PT, Larson MG, Burke GL, Launer LJ, Hofman A, Levy D, Gottdiener JS, Kääb S, Couper D, Harris TB, Soliman EZ, Stricker BH, Gudnason V, Heckbert SR, Benjamin EJ | title = Simple risk model predicts incidence of atrial fibrillation in a racially and geographically diverse population: the CHARGE-AF consortium | journal = Journal of the American Heart Association | volume = 2 | issue = 2 | pages = e000102 | date = March 2013 | pmid = 23537808 | pmc = 3647274 | doi = 10.1161/JAHA.112.000102 }}

There is a relationship between risk factors such as obesity and hypertension, with the appearance of diseases such as diabetes mellitus and sleep apnea-hypopnea syndrome, specifically, obstructive sleep apnea (OSA). These diseases are associated with an increased risk of AF due to their remodeling effects on the left atrium.

Several medications are associated with an increased risk of developing atrial fibrillation.{{cite journal | vauthors = Gorenek B, Pelliccia A, Benjamin EJ, Boriani G, Crijns HJ, Fogel RI, Van Gelder IC, Halle M, Kudaiberdieva G, Lane DA, Larsen TB, Lip GY, Løchen ML, Marín F, Niebauer J, Sanders P, Tokgozoglu L, Vos MA, Van Wagoner DR, Fauchier L, Savelieva I, Goette A, Agewall S, Chiang CE, Figueiredo M, Stiles M, Dickfeld T, Patton K, Piepoli M, Corra U, Marques-Vidal PM, Faggiano P, Schmid JP, Abreu A | title = European Heart Rhythm Association (EHRA)/European Association of Cardiovascular Prevention and Rehabilitation (EACPR) position paper on how to prevent atrial fibrillation endorsed by the Heart Rhythm Society (HRS) and Asia Pacific Heart Rhythm Society (APHRS) | journal = Europace | volume = 19 | issue = 2 | pages = 190–225 | date = February 2017 | pmid = 28175283 | pmc = 6279109 | doi = 10.1093/europace/euw242 | type = Review }} Few studies have examined this phenomenon, and the exact incidence of medication-induced atrial fibrillation is unknown. Medications that are commonly associated with an increased risk of developing atrial fibrillation include dobutamine and the chemotherapy agent cisplatin. Agents associated with a moderately increased risk include nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), bisphosphonates, and other chemotherapeutic agents such as melphalan, interleukin 2, and anthracyclines. Other medications that rarely increase the risk of developing atrial fibrillation include adenosine, aminophylline, corticosteroids, ivabradine, ondansetron, and antipsychotics. This form of atrial fibrillation occurs in people of all ages but is most common in the elderly, in those with other atrial fibrillation risk factors, and after heart surgery.

The normal electrical conduction system of the heart allows electrical impulses generated by the heart's own pacemaker (the sinoatrial node) to spread to and stimulate the muscular layer of the heart (myocardium) in both the atria and the ventricles. When the myocardium is stimulated it contracts, and if this occurs in an orderly manner allows blood to be pumped to the body. In AF, the normal regular electrical impulses generated by the sinoatrial node are overwhelmed by disorganized electrical waves, usually originating from the roots of the pulmonary veins. These disorganized waves conduct intermittently through the atrioventricular node, leading to irregular activation of the ventricles that generate the heartbeat.{{citation needed|date=September 2022}}

The primary pathologic change seen in atrial fibrillation is the progressive fibrosis of the atria. This fibrosis is due primarily to atrial dilation; however, genetic causes and inflammation may be factors in some individuals. Dilation of the atria can be due to almost any structural abnormality of the heart that can cause a rise in the pressure within the heart. This includes valvular heart disease (such as mitral stenosis, mitral regurgitation, and tricuspid regurgitation), hypertension, and congestive heart failure. Any inflammatory state that affects the heart can cause fibrosis of the atria.

Once dilation of the atria has occurred, this begins a chain of events that leads to the activation of the renin–angiotensin–aldosterone system (RAAS) and subsequent increase in the matrix metalloproteinases and disintegrin, which leads to atrial remodeling and fibrosis, with loss of atrial muscle mass. This process occurs gradually, and experimental studies have revealed patchy atrial fibrosis may precede the occurrence of atrial fibrillation and may progress with prolonged durations of atrial fibrillation.{{citation needed|date=September 2022}}

Fibrosis is not limited to the muscle mass of the atria and may occur in the sinus node (SA node) and atrioventricular node (AV node), correlating with sick sinus syndrome. Prolonged episodes of atrial fibrillation have been shown to correlate with prolongation of the sinus node recovery time; this suggests that dysfunction of the SA node is progressive with prolonged episodes of atrial fibrillation.

Along with fibrosis, alterations in the atria that predispose to atrial fibrillation affect their electrical properties, as well as their responsiveness to the autonomic nervous system. The atrial remodeling that includes the pathologic changes described above has been referred to as atrial myopathy.{{cite journal | vauthors = Shen MJ, Arora R, Jalife J | title = Atrial Myopathy | journal = JACC. Basic to Translational Science | volume = 4 | issue = 5 | pages = 640–654 | date = September 2019 | pmid = 31768479 | pmc = 6872845 | doi = 10.1016/j.jacbts.2019.05.005 }}

There are multiple theories about the cause of atrial fibrillation. An important theory is that the regular impulses produced by the sinus node for a normal heartbeat are overwhelmed by rapid electrical discharges produced in the atria and adjacent parts of the pulmonary veins. Non-pulmonary vein sources of triggers for atrial fibrillation have been identified in 10% to 33% of patients. These triggers include the coronary sinus, the posterior wall of the left atrium, the ligament of Marshall, and the left atrial appendage.

Sources of these disturbances are either automatic foci, often localized at one of the pulmonary veins, or a small number of localized sources in the form of either a re-entrant leading circle or electrical spiral waves (rotors); these localized sources may be in the left atrium near the pulmonary veins or in a variety of other locations through both the left or right atrium. Three fundamental components favor the establishment of a leading circle or a rotor: slow conduction velocity of the cardiac action potential, a short refractory period, and a small wavelength. Meanwhile, the wavelength is the product of velocity and refractory period. If the action potential has fast conduction, with a long refractory period and/or conduction pathway shorter than the wavelength, an AF focus would not be established. In multiple wavelet theory, a wavefront will break into smaller daughter wavelets when encountering an obstacle, through a process called vortex shedding. But, under the proper conditions, such wavelets can reform and spin around a center, forming an AF focus.{{cite journal | vauthors = Waks JW, Josephson ME | title = Mechanisms of Atrial Fibrillation - Reentry, Rotors and Reality | journal = Arrhythmia & Electrophysiology Review | volume = 3 | issue = 2 | pages = 90–100 | date = August 2014 | pmid = 26835073 | pmc = 4711504 | doi = 10.15420/aer.2014.3.2.90 }}

In a heart with AF, the increased calcium release from the sarcoplasmic reticulum and increased calcium sensitivity can lead to an accumulation of intracellular calcium and causes downregulation of L-type calcium channels. This reduces the duration of action potential and the refractory period, thus favoring the conduction of re-entrant waves. Increased expression of inward-rectifier potassium ion channels can cause a reduced atrial refractory period and wavelength. The abnormal distribution of gap junction proteins such as GJA1 (also known as connexin 43), and GJA5 (connexin 40) causes non-uniformity of electrical conduction, thus causing the arrhythmia.{{cite journal | vauthors = Pellman J, Sheikh F | title = Atrial fibrillation: mechanisms, therapeutics, and future directions | journal = Comprehensive Physiology | volume = 5 | issue = 2 | pages = 649–665 | date = April 2015 | pmid = 25880508 | pmc = 5240842 | doi = 10.1002/cphy.c140047 | isbn = 978-0-470-65071-4 }}

AF can be distinguished from atrial flutter (AFL), which appears as an organized electrical circuit usually in the right atrium. AFL produces characteristic saw-toothed F-waves of constant amplitude and frequency on an ECG, whereas AF does not. In AFL, the discharges circulate rapidly at a rate of 300 beats per minute (bpm) around the atrium. In AF, there is no such regularity, except at the sources where the local activation rate can exceed 500 bpm. Although AF and atrial flutter are distinct arrhythmias, atrial flutter may degenerate into AF, and an individual may experience both arrhythmias at different times.

Although the electrical impulses of AF occur at a high rate, most of them do not result in a heartbeat. A heartbeat results when an electrical impulse from the atria passes through the atrioventricular (AV) node to the ventricles and causes them to contract. During AF, if all of the impulses from the atria passed through the AV node, there would be severe ventricular tachycardia, resulting in a severe reduction of cardiac output. This dangerous situation is prevented by the AV node since its limited conduction velocity reduces the rate at which impulses reach the ventricles during AF.{{cite book | vauthors = Klabunde R |title = Cardiovascular Physiology Concepts |publisher = Lippincott Williams & Wilkins |year = 2005 |pages = [https://archive.org/details/cardiovascularph00klab_564/page/n24 25], 28 |url =https://archive.org/details/cardiovascularph00klab_564|url-access = limited |isbn = 978-0-7817-5030-1 }}

File:ECG Atrial Fibrillation.jpg

Image:SinusRhythmLabels.svg as seen on ECG. In atrial fibrillation the P waves, which represent depolarization of the top of the heart, are absent.]]

Atrial fibrillation is diagnosed on an electrocardiogram (ECG/EKG). The evaluation of atrial fibrillation involves a determination of the cause of the arrhythmia, and classification of the arrhythmia. Diagnostic investigation of AF typically includes a complete medical history and physical examination, ECG, transthoracic echocardiogram and blood tests.

Numerous guidelines recommend opportunistic screening for atrial fibrillation in those 65 years and older. These organizations include the: European Society of Cardiology,{{cite journal | vauthors = Hindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomström-Lundqvist C, Boriani G, Castella M, Dan GA, Dilaveris PE, Fauchier L, Filippatos G, Kalman JM, La Meir M, Lane DA, Lebeau JP, Lettino M, Lip GY, Pinto FJ, Thomas GN, Valgimigli M, Van Gelder IC, Van Putte BP, Watkins CL | title = 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC | journal = European Heart Journal | volume = 42 | issue = 5 | pages = 373–498 | date = February 2021 | pmid = 32860505 | doi = 10.1093/eurheartj/ehaa612 | hdl-access = free | doi-access = free | others = ESC Scientific Document Group | hdl = 1887/3279676 }}

National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand,{{cite journal | vauthors = Brieger D, Amerena J, Attia J, Bajorek B, Chan KH, Connell C, Freedman B, Ferguson C, Hall T, Haqqani H, Hendriks J, Hespe C, Hung J, Kalman JM, Sanders P, Worthington J, Yan TD, Zwar N | title = National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand: Australian Clinical Guidelines for the Diagnosis and Management of Atrial Fibrillation 2018 | journal = Heart, Lung & Circulation | volume = 27 | issue = 10 | pages = 1209–1266 | date = October 2018 | pmid = 30077228 | doi = 10.1016/j.hlc.2018.06.1043 | hdl-access = free | doi-access = free | hdl = 10536/DRO/DU:30157490 }}

European Heart Rhythm Society,{{cite journal | vauthors = Kirchhof P, Breithardt G, Bax J, Benninger G, Blomstrom-Lundqvist C, Boriani G, Brandes A, Brown H, Brueckmann M, Calkins H, Calvert M, Christoffels V, Crijns H, Dobrev D, Ellinor P, Fabritz L, Fetsch T, Freedman SB, Gerth A, Goette A, Guasch E, Hack G, Haegeli L, Hatem S, Haeusler KG, Heidbüchel H, Heinrich-Nols J, Hidden-Lucet F, Hindricks G, Juul-Möller S, Kääb S, Kappenberger L, Kespohl S, Kotecha D, Lane DA, Leute A, Lewalter T, Meyer R, Mont L, Münzel F, Nabauer M, Nielsen JC, Oeff M, Oldgren J, Oto A, Piccini JP, Pilmeyer A, Potpara T, Ravens U, Reinecke H, Rostock T, Rustige J, Savelieva I, Schnabel R, Schotten U, Schwichtenberg L, Sinner MF, Steinbeck G, Stoll M, Tavazzi L, Themistoclakis S, Tse HF, Van Gelder IC, Vardas PE, Varpula T, Vincent A, Werring D, Willems S, Ziegler A, Lip GY, Camm AJ | title = A roadmap to improve the quality of atrial fibrillation management: proceedings from the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference | journal = Europace | volume = 18 | issue = 1 | pages = 37–50 | date = January 2016 | pmid = 26481149 | doi = 10.1093/europace/euv304 }}{{cite journal | vauthors = Mairesse GH, Moran P, Van Gelder IC, Elsner C, Rosenqvist M, Mant J, Banerjee A, Gorenek B, Brachmann J, Varma N, Glotz de Lima G, Kalman J, Claes N, Lobban T, Lane D, Lip GY, Boriani G | title = Screening for atrial fibrillation: a European Heart Rhythm Association (EHRA) consensus document endorsed by the Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLAECE) | journal = Europace | volume = 19 | issue = 10 | pages = 1589–1623 | date = October 2017 | pmid = 29048522 | doi = 10.1093/europace/eux177 | doi-access = free }}

AF-SCREEN International Collaboration,{{cite journal | vauthors = Freedman B, Camm J, Calkins H, Healey JS, Rosenqvist M, Wang J, Albert CM, Anderson CS, Antoniou S, Benjamin EJ, Boriani G, Brachmann J, Brandes A, Chao TF, Conen D, Engdahl J, Fauchier L, Fitzmaurice DA, Friberg L, Gersh BJ, Gladstone DJ, Glotzer TV, Gwynne K, Hankey GJ, Harbison J, Hillis GS, Hills MT, Kamel H, Kirchhof P, Kowey PR, Krieger D, Lee VW, Levin LÅ, Lip GY, Lobban T, Lowres N, Mairesse GH, Martinez C, Neubeck L, Orchard J, Piccini JP, Poppe K, Potpara TS, Puererfellner H, Rienstra M, Sandhu RK, Schnabel RB, Siu CW, Steinhubl S, Svendsen JH, Svennberg E, Themistoclakis S, Tieleman RG, Turakhia MP, Tveit A, Uittenbogaart SB, Van Gelder IC, Verma A, Wachter R, Yan BP | title = Screening for Atrial Fibrillation: A Report of the AF-SCREEN International Collaboration | journal = Circulation | volume = 135 | issue = 19 | pages = 1851–1867 | date = May 2017 | pmid = 28483832 | doi = 10.1161/CIRCULATIONAHA.116.026693 | author61 = ((AF-Screen Collaborators)) | s2cid = 207655707 | doi-access = free | hdl = 11380/1139441 | hdl-access = free }}

Royal College of Physicians of Edinburgh{{cite journal | vauthors = Stott DJ, Dewar RI, Garratt CJ, Griffith KE, Harding NJ, James MA, Lane DA, Petty DR, Smith PA, Somerville MH, Trueland J | title = RCPE UK Consensus Conference on 'approaching the comprehensive management of atrial fibrillation: evolution or revolution?' | journal = The Journal of the Royal College of Physicians of Edinburgh | volume = 42 | issue = 1 | pages = 34–35 | date = March 2012 | pmid = 22441062 | doi = 10.4997/JRCPE.2012.S01 | doi-access = free }}

European Primary Care Cardiovascular Society,{{cite journal | vauthors = Hobbs FR, Taylor CJ, Jan Geersing G, Rutten FH, Brouwer JR | title = European Primary Care Cardiovascular Society (EPCCS) consensus guidance on stroke prevention in atrial fibrillation (SPAF) in primary care | journal = European Journal of Preventive Cardiology | volume = 23 | issue = 5 | pages = 460–473 | date = March 2016 | pmid = 25701017 | pmc = 4766963 | doi = 10.1177/2047487315571890 | doi-access = free }} and Irish Health Information and Quality Authority.{{cite web |title=Reports and Publications {{!}} HIQA |url=https://www.hiqa.ie/publications/health-technology-assessment-hta-national-screening-programme-atrial-fibrillation-prima |website=www.hiqa.ie}}

Single timepoint screening detects undiagnosed AF, which is often asymptomatic, in approximately 1.4% of people in people aged 65 years and older.{{cite journal | vauthors = Lowres N, Olivier J, Chao TF, Chen SA, Chen Y, Diederichsen A, Fitzmaurice DA, Gomez-Doblas JJ, Harbison J, Healey JS, Hobbs FD, Kaasenbrood F, Keen W, Lee VW, Lindholt JS, Lip GY, Mairesse GH, Mant J, Martin JW, Martín-Rioboó E, McManus DD, Muñiz J, Münzel T, Nakamya J, Neubeck L, Orchard JJ, Pérula de Torres LÁ, Proietti M, Quinn FR, Roalfe AK, Sandhu RK, Schnabel RB, Smyth B, Soni A, Tieleman R, Wang J, Wild PS, Yan BP, Freedman B | title = Estimated stroke risk, yield, and number needed to screen for atrial fibrillation detected through single time screening: a multicountry patient-level meta-analysis of 141,220 screened individuals | journal = PLOS Medicine | volume = 16 | issue = 9 | pages = e1002903 | date = September 2019 | pmid = 31553733 | pmc = 6760766 | doi = 10.1371/journal.pmed.1002903 | doi-access = free }} In 2022, the United States Preventive Services Task Force found insufficient evidence to determine the usefulness of routine screening.{{cite journal |vauthors=Davidson KW, Barry MJ, Mangione CM, Cabana M, Caughey AB, Davis EM, Donahue KE, Doubeni CA |others = US Preventive Services Task Force |title=Screening for Atrial Fibrillation: US Preventive Services Task Force Recommendation Statement |journal=JAMA |volume=327 |issue=4 |date=25 January 2022 |issn=0098-7484 |doi=10.1001/jama.2021.23732 |doi-access=free |page=360 |pmid = 35076659 }}

Some smartwatches may detect AF.{{cite journal | vauthors = Pay L, Yumurtaş AÇ, Satti DI, Hui JM, Chan JS, Mahalwar G, Lee YH, Tezen O, Birdal O, Inan D, Özkan E, Tse G, Çinier G | title = Arrhythmias Beyond Atrial Fibrillation Detection Using Smartwatches: A Systematic Review | journal = Anatolian Journal of Cardiology | volume = 27 | issue = 3 | pages = 126–131 | date = March 2023 | pmid = 36856589 | pmc = 9995551 | doi = 10.14744/anatoljcardiol.2023.2799 | publisher = Kare Publishing }}

Blood tests such as complete blood count, kidney function, electrolytes, glucose or HbA1c, and thyroid function is often determined in new-onset atrial fibrillation, to provide risk stratification and exclude certain etiology.

File:Atrial Fibrillation.png

Atrial fibrillation is diagnosed on an electrocardiogram (ECG), an investigation performed routinely whenever an irregular heartbeat is suspected. Characteristic findings are the absence of P waves, with disorganized electrical activity in their place, and irregular R–R intervals due to irregular conduction of impulses to the ventricles. At very fast heart rates, atrial fibrillation may look more regular, which may make it more difficult to separate from other supraventricular tachycardias or ventricular tachycardia.{{cite book | vauthors = Issa ZF, Miller JM, Zipes DP |title = Clinical arrhythmology and electrophysiology: a companion to Braunwald's heart disease |year = 2009 |publisher = Saunders |location = Philadelphia |isbn = 978-1-4160-5998-1 |page = 221 |url = https://books.google.com/books?id=a8s8nd2JAiwC&pg=PA221 |url-status = live |archive-url = https://web.archive.org/web/20170908144250/https://books.google.com/books?id=a8s8nd2JAiwC&pg=PA221 |archive-date = 8 September 2017 }}

QRS complexes should be narrow, signifying that they are initiated by normal conduction of atrial electrical activity through the intraventricular conduction system. Wide QRS complexes are worrisome for ventricular tachycardia, although, in cases where there is a disease of the conduction system, wide complexes may be present in A-fib with a rapid ventricular response.

If paroxysmal AF is suspected, but an ECG during an office visit shows only a regular rhythm, AF episodes may be detected and documented with the use of ambulatory Holter monitoring (e.g., for a day). If the episodes are too infrequent to be detected by Holter monitoring with reasonable probability, then the person can be monitored for longer periods (e.g., a month) with an ambulatory event monitor.

In general, a non-invasive transthoracic echocardiogram (TTE) is performed in newly diagnosed AF, as well as if there is a major change in the person's clinical state. This ultrasound-based scan of the heart may help identify valvular heart disease (which may greatly increase the risk of stroke and alter recommendations for the appropriate type of anticoagulation), left and right atrial size (which predicts the likelihood that AF may become permanent), left ventricular size and function, peak right ventricular pressure (pulmonary hypertension), presence of left atrial thrombus (low sensitivity), presence of left ventricular hypertrophy and pericardial disease.

Significant enlargement of both the left and right atria is associated with long-standing atrial fibrillation and, if noted at the initial presentation of atrial fibrillation, suggests that the atrial fibrillation is likely to be of a longer duration than the individual's symptoms.{{citation needed|date=September 2022}}

A regular echocardiogram (transthoracic echocardiogram; TTE) has a low sensitivity for identifying blood clots in the heart. If this is suspected (e.g. when planning urgent electrical cardioversion), a transesophageal echocardiogram (TEE, or TOE where British spelling is used) is preferred.

The TEE has much better visualization of the left atrial appendage than transthoracic echocardiography.{{cite journal | vauthors = Romero J, Cao JJ, Garcia MJ, Taub CC | title = Cardiac imaging for assessment of left atrial appendage stasis and thrombosis | journal = Nature Reviews. Cardiology | volume = 11 | issue = 8 | pages = 470–480 | date = August 2014 | pmid = 24913058 | doi = 10.1038/nrcardio.2014.77 | s2cid = 29114242 }} This structure, located in the left atrium, is the place where a blood clot forms in more than 90% of cases in non-valvular (or non-rheumatic) atrial fibrillation.{{cite journal | vauthors = Ramlawi B, Abu Saleh WK, Edgerton J | title = The Left Atrial Appendage: Target for Stroke Reduction in Atrial Fibrillation | journal = Methodist DeBakey Cardiovascular Journal | volume = 11 | issue = 2 | pages = 100–103 | date = 2015 | pmid = 26306127 | pmc = 4547664 | doi = 10.14797/mdcj-11-2-100 }} TEE has a high sensitivity for locating thrombi in this area and can also detect sluggish blood flow in this area that is suggestive of blood clot formation. If a blood clot is seen on TEE, then cardioversion is contraindicated due to the risk of stroke, and anticoagulation is recommended.

A Holter monitor is a wearable ambulatory heart monitor that continuously monitors the heart rate and heart rhythm for a short duration, typically 24 hours. In individuals with symptoms of significant shortness of breath with exertion or palpitations regularly, a Holter monitor may be of benefit to determine whether rapid heart rates (or unusually slow heart rates) during atrial fibrillation are the cause of the symptoms.

The American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC) recommend in their guidelines the following classification system based on simplicity and clinical relevance.

All people with AF are initially in the category called first detected AF. These people may or may not have had previous undetected episodes. If a first detected episode stops on its own in less than seven days and then another episode begins, later on, the category changes to paroxysmal AF. Although people in this category have episodes lasting up to seven days, in most cases of paroxysmal AF, the episodes will stop in less than 24 hours. If the episode lasts for more than seven days, it is unlikely to stop on its own and is then known as persistent AF. In this case, cardioversion can be attempted to restore a normal rhythm. If an episode continues for a year or more, the rhythm is then known as long-standing persistent AF. If a decision is made by the person and their medical team to accept persistent AF and not attempt restoration of a normal sinus rhythm but instead manage the AF by simply controlling the person's ventricular rate then the rhythm is referred to as permanent AF. As a further subtype, AF that is detected only by an implanted or wearable cardiac monitor is known as subclinical AF.

Episodes that last less than 30 seconds are not considered in this classification system. Also, this system does not apply to cases where the AF is a secondary condition that occurs in the setting of a primary condition that may be the cause of the AF.

About half of people with AF have permanent AF, while a quarter have paroxysmal AF, and a quarter have persistent AF.

In addition to the above AF categories, which are mainly defined by episode timing and termination, the ACC/AHA and ESC guidelines describe additional outdated AF categories in terms of other characteristics of the person. Valvular AF refers to AF attributable to moderate to severe mitral valve stenosis or atrial fibrillation in the presence of a mechanical artificial heart valve. This distinction may be useful as it has implications on appropriate treatment, including differing recommendations for anticoagulation, but the term is discouraged as it may be confusing. Other historically used definitions include lone AF – AF occurring in those aged under 60 in the absence of other cardiovascular or respiratory diseases. This description is also discouraged since it offers no clinical value. Secondary AF refers to AF that occurs in the setting of another condition that have caused the AF, such as acute myocardial infarction, cardiac surgery, pericarditis, myocarditis, hyperthyroidism, pulmonary embolism, pneumonia, or another acute pulmonary disease.

Prevention of atrial fibrillation focuses primarily on preventing or controlling its risk factors. Many of its risk factors, such as obesity, smoking, lack of physical activity, and excessive alcohol consumption, are modifiable and preventable with lifestyle modification or can be managed by a healthcare professional.

Several healthy lifestyle behaviors are associated with a lower likelihood of developing atrial fibrillation. Accordingly, consensus guidelines recommend abstaining from alcohol and recreational drugs, stopping tobacco use, maintaining a healthy weight, and regularly participating in moderate-intensity physical activities. Consistent moderate-intensity aerobic exercise, defined as achieving 3.0–5.9 METs of intensity, for at least 150 minutes per week may reduce the risk of developing new-onset atrial fibrillation. Few studies have examined the role of specific dietary changes and how it relates to the prevention of atrial fibrillation.

The main goals of treatment are to prevent circulatory instability and stroke. Rate or rhythm control is used to achieve the former, whereas anticoagulation is used to decrease the risk of the latter.{{cite journal | vauthors = Prystowsky EN, Padanilam BJ, Fogel RI | title = Treatment of Atrial Fibrillation | journal = JAMA | volume = 314 | issue = 3 | pages = 278–288 | date = July 2015 | pmid = 26197188 | doi = 10.1001/jama.2015.7505 | s2cid = 205070036 }} If cardiovascularly unstable due to uncontrolled tachycardia, immediate cardioversion is indicated. Many antiarrhythmics, when used long term, increase the risk of death without any meaningful benefit.{{cite journal | vauthors = Valembois L, Audureau E, Takeda A, Jarzebowski W, Belmin J, Lafuente-Lafuente C | title = Antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | issue = 9 | pages = CD005049 | date = September 2019 | pmid = 31483500 | pmc = 6738133 | doi = 10.1002/14651858.CD005049.pub5 }} An integrated management approach, which includes stroke prevention, symptoms control and management of associated comorbidities has been associated with better outcomes in patients with atrial fibrillation.{{cite journal | vauthors = Romiti GF, Pastori D, Rivera-Caravaca JM, Ding WY, Gue YX, Menichelli D, Gumprecht J, Kozieł M, Yang PS, Guo Y, Lip GY, Proietti M | title = Adherence to the 'Atrial Fibrillation Better Care' Pathway in Patients with Atrial Fibrillation: Impact on Clinical Outcomes-A Systematic Review and Meta-Analysis of 285,000 Patients | journal = Thrombosis and Haemostasis | volume = 122 | issue = 3 | pages = 406–414 | date = March 2022 | pmid = 34020488 | doi = 10.1055/A-1515-9630 | hdl-access = free | doi-access = free | hdl = 2434/887644 }}{{cite journal | vauthors = Proietti M, Romiti GF, Olshansky B, Lane DA, Lip GY | title = Improved Outcomes by Integrated Care of Anticoagulated Patients with Atrial Fibrillation Using the Simple ABC (Atrial Fibrillation Better Care) Pathway | journal = The American Journal of Medicine | volume = 131 | issue = 11 | pages = 1359–1366.e6 | date = November 2018 | pmid = 30153428 | doi = 10.1016/j.amjmed.2018.06.012 | hdl = 2183/31714 | s2cid = 52114134 | url = http://pure-oai.bham.ac.uk/ws/files/54246094/Proietti_et_al_Improved_outcomes_by_intergrated_The_American_Journal_of_Medicine_2018.pdf }}{{cite journal | vauthors = Proietti M, Romiti GF, Olshansky B, Lane DA, Lip GY | title = Comprehensive Management With the ABC (Atrial Fibrillation Better Care) Pathway in Clinically Complex Patients With Atrial Fibrillation: A Post Hoc Ancillary Analysis From the AFFIRM Trial | journal = Journal of the American Heart Association | volume = 9 | issue = 10 | pages = e014932 | date = May 2020 | pmid = 32370588 | pmc = 7660878 | doi = 10.1161/JAHA.119.014932 | doi-access = free }}{{cite journal | vauthors = Pastori D, Pignatelli P, Menichelli D, Violi F, Lip GY | title = Integrated Care Management of Patients With Atrial Fibrillation and Risk of Cardiovascular Events: The ABC (Atrial fibrillation Better Care) Pathway in the ATHERO-AF Study Cohort | journal = Mayo Clinic Proceedings | volume = 94 | issue = 7 | pages = 1261–1267 | date = July 2019 | pmid = 30551910 | doi = 10.1016/j.mayocp.2018.10.022 | s2cid = 54623946 }}

This holistic or integrated care approach is summed up as the ABC (Atrial fibrillation Better Care) pathway,{{cite journal | vauthors = Lip GY | title = The ABC pathway: an integrated approach to improve AF management | journal = Nature Reviews. Cardiology | volume = 14 | issue = 11 | pages = 627–628 | date = November 2017 | pmid = 28960189 | doi = 10.1038/nrcardio.2017.153 | s2cid = 36013527 }} as follows:

• A: Avoid stroke with Anticoagulation, where the default is stroke prevention unless the patient is at low risk. Stroke prevention means use of oral anticoagulation (OAC), whether with well managed vitamin K antagonists (VKA), with time in therapeutic range >70%, or more commonly, label-adherent dosed direct oral anticoagulant (DOAC).
• B: Better symptom and atrial fibrillation management with patient-centred, symptom directed decisions on rate control or rhythm control. In some selected patients, use early rhythm control may be beneficial.
• C: Cardiovascular risk factor and comorbidity management, including attention to lifestyle factors and psychological morbidity.

Regular aerobic exercise improves atrial fibrillation symptoms and AF-related quality of life. The effect of high-intensity interval training on reducing atrial fibrillation burden is unclear. Weight loss of at least 10% is associated with reduced atrial fibrillation burden in people who are overweight or obese.

For people who have both atrial fibrillation and obstructive sleep apnea, observational studies suggest that continuous positive airway pressure (CPAP) treatment appears to lower the risk of atrial fibrillation recurrence after undergoing ablation. Randomized controlled trials examining the role of obstructive sleep apnea treatment on atrial fibrillation incidence and burden are lacking. Guideline-recommended lifestyle and medical interventions are recommended for people with atrial fibrillation and coexisting conditions such as hyperlipidemia, diabetes mellitus, or hypertension without specific blood sugar or blood pressure targets for people with atrial fibrillation.

Bariatric surgery may reduce the risk of new-onset atrial fibrillation in people with obesity without AF and may reduce the risk of a recurrence of AF after an ablation procedure in people with coexisting obesity and atrial fibrillation. It is important for all people with atrial fibrillation to optimize the control of all coexisting medical conditions that can worsen their atrial fibrillation, such as hyperthyroidism, diabetes, congestive heart failure,{{cite journal | vauthors = Verma A, Kalman JM, Callans DJ | title = Treatment of Patients With Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction | journal = Circulation | volume = 135 | issue = 16 | pages = 1547–1563 | date = April 2017 | pmid = 28416525 | doi = 10.1161/CIRCULATIONAHA.116.026054 | s2cid = 207646320 | doi-access = free }} high blood pressure,{{cite journal | vauthors = Verdecchia P, Angeli F, Reboldi G | title = Hypertension and Atrial Fibrillation: Doubts and Certainties From Basic and Clinical Studies | journal = Circulation Research | volume = 122 | issue = 2 | pages = 352–368 | date = January 2018 | pmid = 29348255 | doi = 10.1161/CIRCRESAHA.117.311402 | s2cid = 33841631 | doi-access = free }} chronic obstructive pulmonary disease,{{cite journal | vauthors = Simons SO, Elliott A, Sastry M, Hendriks JM, Arzt M, Rienstra M, Kalman JM, Heidbuchel H, Nattel S, Wesseling G, Schotten U, van Gelder IC, Franssen FM, Sanders P, Crijns HJ, Linz D | title = Chronic obstructive pulmonary disease and atrial fibrillation: an interdisciplinary perspective | journal = European Heart Journal | volume = 42 | issue = 5 | pages = 532–540 | date = February 2021 | pmid = 33206945 | doi = 10.1093/eurheartj/ehaa822 | hdl-access = free | hdl = 1942/35482 }}{{cite journal | vauthors = Romiti GF, Corica B, Pipitone E, Vitolo M, Raparelli V, Basili S, Boriani G, Harari S, Lip GY, Proietti M | title = Prevalence, management and impact of chronic obstructive pulmonary disease in atrial fibrillation: a systematic review and meta-analysis of 4,200,000 patients | journal = European Heart Journal | volume = 42 | issue = 35 | pages = 3541–3554 | date = September 2021 | pmid = 34333599 | doi = 10.1093/eurheartj/ehab453 | hdl-access = free | doi-access = free | hdl = 2434/887636 }} stimulant use (e.g., methamphetamine dependence), and excessive alcohol consumption.{{cite journal | vauthors = Voskoboinik A, Kalman JM, De Silva A, Nicholls T, Costello B, Nanayakkara S, Prabhu S, Stub D, Azzopardi S, Vizi D, Wong G, Nalliah C, Sugumar H, Wong M, Kotschet E, Kaye D, Taylor AJ, Kistler PM | title = Alcohol Abstinence in Drinkers with Atrial Fibrillation | journal = The New England Journal of Medicine | volume = 382 | issue = 1 | pages = 20–28 | date = January 2020 | pmid = 31893513 | doi = 10.1056/NEJMoa1817591 | doi-access = free }}

Anticoagulation medication can be used to reduce the risk of stroke from AF. Anticoagulation medication is recommended in most people with increased risk of stroke,{{Cite report |pmid=30480925 | vauthors = Sanders GD, Lowenstern A, Borre E, Chatterjee R, Goode A, Sharan L, Lapointe NA, Raitz G, Shah B, Yapa R, Davis JK | title = Stroke prevention in patients with atrial fibrillation: a systematic review update. | location = Rockville (MD) | work = Agency for Healthcare Research and Quality (US) | date = October 2018 | quote = Report No.: 18-EHC018-EFReport No.: 2018-SR-04 | series = AHRQ Comparative Effectiveness Reviews. }}{{cite journal | vauthors = Lip GY, Lane DA | title = Stroke prevention in atrial fibrillation: a systematic review | journal = JAMA | volume = 313 | issue = 19 | pages = 1950–1962 | date = May 2015 | pmid = 25988464 | doi = 10.1001/jama.2015.4369 }} which can be estimated using the CHA₂DS₂-VASc score.

The risk of falls and consequent bleeding in frail elderly people should not be considered a barrier to initiating or continuing anticoagulation since the risk of fall-related brain bleeding is low and the benefit of stroke prevention often outweighs the risk of bleeding.{{cite journal | vauthors = Zarraga IG, Kron J | title = Oral anticoagulation in elderly adults with atrial fibrillation: integrating new options with old concepts | journal = Journal of the American Geriatrics Society | volume = 61 | issue = 1 | pages = 143–150 | date = January 2013 | pmid = 23252345 | doi = 10.1111/jgs.12042 | s2cid = 34366717 }} The presence or absence of AF symptoms does not determine whether a person warrants anticoagulation and is not an indicator of stroke risk.{{cite journal | vauthors = Argulian E, Conen D, Messerli FH | title = Misconceptions and Facts About Atrial Fibrillation | journal = The American Journal of Medicine | volume = 128 | issue = 9 | pages = 938–942 | date = September 2015 | pmid = 25827359 | doi = 10.1016/j.amjmed.2015.02.016 }}

Direct oral anticoagulant (DOAC) are recommended over warfarin in atrial fibrillation.{{Cite journal |vauthors= Joglar JA, Chung MK, Armbruster AL, Benjamin EJ, Chyou JY, Cronin EM, Deswal A, Eckhardt LL, Goldberger ZD, Gopinathannair R, Gorenek B, Hess PL, Hlatky MH, Hogan G, Ibeh C, Indik JH, Kido K, Kusumoto F, Link MS, Linta KT, Marcus GM, McCarthy PM, Patel N, Patton KK, Perez MV, Piccini JP, Russo AM, Sanders P, Streur MM, Thomas KL, Times S, Tisdale JE, Valente AM, Van Wagoner DR |date=30 November 2023 |title=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 |journal=Circulation |language=en |volume=149 |issue=1 |pages=e1–e156 |doi=10.1161/CIR.0000000000001193 |doi-access=free |pmc=11095842 |pmid=38033089 }} In atrial fibrillation with presence of moderate to severe mitral stenosis or mechanical heart valve, warfarin is recommended over other therapies. DOACs carry a lower risk of bleeding in the brain compared to warfarin,{{cite journal | vauthors = Kundu A, Sardar P, Chatterjee S, Aronow WS, Owan T, Ryan JJ | title = Minimizing the Risk of Bleeding with NOACs in the Elderly | journal = Drugs & Aging | volume = 33 | issue = 7 | pages = 491–500 | date = July 2016 | pmid = 27174293 | doi = 10.1007/s40266-016-0376-z | s2cid = 3832073 }} although dabigatran is associated with a higher risk of intestinal bleeding.{{cite journal | vauthors = Sharma M, Cornelius VR, Patel JP, Davies JG, Molokhia M | title = Efficacy and Harms of Direct Oral Anticoagulants in the Elderly for Stroke Prevention in Atrial Fibrillation and Secondary Prevention of Venous Thromboembolism: Systematic Review and Meta-Analysis | journal = Circulation | volume = 132 | issue = 3 | pages = 194–204 | date = July 2015 | pmid = 25995317 | pmc = 4765082 | doi = 10.1161/CIRCULATIONAHA.114.013267 }}

Direct oral anticoagulant (DOAC), previously called "new", "novel", or "non-vitamin K antagonist" oral anticoagulant (NOAC), are medications taken orally that have another mechanism of action on the coagulation cascade than warfarin.{{Cite journal |last1=Barnes |first1=G. D. |last2=Ageno |first2=W. |last3=Ansell |first3=J. |last4=Kaatz |first4=S. |date=2015-06-01 |title=Recommendation on the nomenclature for oral anticoagulants: communication from the SSC of the ISTH |journal=Journal of Thrombosis and Haemostasis |language=English |volume=13 |issue=6 |pages=1154–1156 |doi=10.1111/jth.12969 |issn=1538-7836 |doi-access=free|pmid=25880598 |hdl=2027.42/111930 |hdl-access=free }} DOACs recommended in atrial fibrillation include apixaban, dabigatran, edoxaban and rivaroxaban.

Antiplatelet drugs alone, such as aspirin or dual antiplatelet therapy with aspirin and clopidogrel, is not recommended as stroke prophylaxis in atrial fibrillation.{{cite journal | title = Guidelines for Pharmacotherapy of Atrial Fibrillation (JCS 2013) | journal = Circulation Journal | volume = 78 | issue = 8 | pages = 1997–2021 | date = August 2014 | pmid = 24965079 | doi = 10.1253/circj.cj-66-0092 | type = Review | doi-access = free | author1 = JCS Joint Working Group }}{{cite journal | vauthors = Jung BC, Kim NH, Nam GB, Park HW, On YK, Lee YS, Lim HE, Joung B, Cha TJ, Hwang GS, Oh S, Kim JS | title = The Korean Heart Rhythm Society's 2014 Statement on Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation: Korean Heart Rhythm Society | journal = Korean Circulation Journal | volume = 45 | issue = 1 | pages = 9–19 | date = January 2015 | pmid = 25653698 | pmc = 4310986 | doi = 10.4070/kcj.2015.45.1.9 | type = Review }}{{cite journal | vauthors = You JJ, Singer DE, Howard PA, Lane DA, Eckman MH, Fang MC, Hylek EM, Schulman S, Go AS, Hughes M, Spencer FA, Manning WJ, Halperin JL, Lip GY | title = Antithrombotic therapy for atrial fibrillation: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines | journal = Chest | volume = 141 | issue = 2 Suppl | pages = e531S–e575S | date = February 2012 | pmid = 22315271 | pmc = 3278056 | doi = 10.1378/chest.11-2304 | type = Review }}{{cite journal | vauthors = Chiang CE, Okumura K, Zhang S, Chao TF, Siu CW, Wei Lim T, Saxena A, Takahashi Y, Siong Teo W | title = 2017 consensus of the Asia Pacific Heart Rhythm Society on stroke prevention in atrial fibrillation | journal = Journal of Arrhythmia | volume = 33 | issue = 4 | pages = 345–367 | date = August 2017 | pmid = 28765771 | pmc = 5529598 | doi = 10.1016/j.joa.2017.05.004 | type = Review }}{{cite journal | vauthors = Macle L, Cairns J, Leblanc K, Tsang T, Skanes A, Cox JL, Healey JS, Bell A, Pilote L, Andrade JG, Mitchell LB, Atzema C, Gladstone D, Sharma M, Verma S, Connolly S, Dorian P, Parkash R, Talajic M, Nattel S, Verma A | title = 2016 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation | journal = The Canadian Journal of Cardiology | volume = 32 | issue = 10 | pages = 1170–1185 | date = October 2016 | pmid = 27609430 | doi = 10.1016/j.cjca.2016.07.591 | doi-access = free }} In those who are also on aspirin, DOACs appear to be better than warfarin.{{cite journal | vauthors = Bennaghmouch N, de Veer AJ, Bode K, Mahmoodi BK, Dewilde WJ, Lip GY, Brueckmann M, Kleine E, Ten Berg JM | title = Efficacy and Safety of the Use of Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Nonvalvular Atrial Fibrillation and Concomitant Aspirin Therapy: A Meta-Analysis of Randomized Trials | journal = Circulation | volume = 137 | issue = 11 | pages = 1117–1129 | date = March 2018 | pmid = 29101289 | doi = 10.1161/CIRCULATIONAHA.117.028513 | s2cid = 24988387 | doi-access = free }}

The optimal approach to anticoagulation in people with AF and who simultaneously have other diseases (e.g., cirrhosis and end-stage kidney disease on dialysis) that predispose a person to both bleeding and clotting complications is unclear.{{cite journal | vauthors = Hu A, Niu J, Winkelmayer WC | title = Oral Anticoagulation in Patients With End-Stage Kidney Disease on Dialysis and Atrial Fibrillation | journal = Seminars in Nephrology | volume = 38 | issue = 6 | pages = 618–628 | date = November 2018 | pmid = 30413255 | pmc = 6233322 | doi = 10.1016/j.semnephrol.2018.08.006 }}{{cite journal | vauthors = Qamar A, Vaduganathan M, Greenberger NJ, Giugliano RP | title = Oral Anticoagulation in Patients With Liver Disease | journal = Journal of the American College of Cardiology | volume = 71 | issue = 19 | pages = 2162–2175 | date = May 2018 | pmid = 29747837 | doi = 10.1016/j.jacc.2018.03.023 | doi-access = free }}

For vitamin K antagonists (VKA) such as warfarin, time in therapeutic range (TTR) and INR variability are commonly used to assess the quality of VKA treatment. Patients who are unable to maintain a therapeutic INR on VKA, as indicated by low TTR and/or high INR variability, are at an increased risk of thromboembolic and bleeding events.{{cite journal | vauthors = Veeger NJ, Piersma-Wichers M, Hillege HL, Crijns HJ, van der Meer J | title = Early detection of patients with a poor response to vitamin K antagonists: the clinical impact of individual time within target range in patients with heart disease | journal = Journal of Thrombosis and Haemostasis | volume = 4 | issue = 7 | pages = 1625–1627 | date = July 2006 | pmid = 16839366 | doi = 10.1111/j.1538-7836.2006.01997.x | doi-access = free }} In these patients, treatment with a DOAC is recommended. While there are no significant changes in adherence, persistence or clinical outcomes in patients switched from a VKA to a DOAC, an increase in therapy satisfaction has been reported.{{cite journal | vauthors = Elling T, Hak E, Bos JH, Tichelaar VY, Veeger NJ, Meijer K | title = Effect of Previous INR Control during VKA Therapy on Subsequent DOAC Adherence and Persistence, in Patients Switched from VKA to DOAC | journal = Thrombosis and Haemostasis | date = October 2023 | volume = 124 | issue = 8 | pages = 778–790 | pmid = 37673103 | doi = 10.1055/a-2168-9378 | doi-access = free | pmc = 11259495 }}{{cite journal | vauthors = Adelakun AR, Turgeon RD, De Vera MA, McGrail K, Loewen PS | title = Oral anticoagulant switching in patients with atrial fibrillation: a scoping review | journal = BMJ Open | volume = 13 | issue = 4 | pages = e071907 | date = April 2023 | pmid = 37185198 | pmc = 10151984 | doi = 10.1136/bmjopen-2023-071907 }}

There are two ways to approach atrial fibrillation using medications: rate control and rhythm control. Both methods have similar outcomes.{{cite journal | vauthors = Al-Khatib SM, Allen LaPointe NM, Chatterjee R, Crowley MJ, Dupre ME, Kong DF, Lopes RD, Povsic TJ, Raju SS, Shah B, Kosinski AS, McBroom AJ, Sanders GD | title = Rate- and rhythm-control therapies in patients with atrial fibrillation: a systematic review | journal = Annals of Internal Medicine | volume = 160 | issue = 11 | pages = 760–773 | date = June 2014 | pmid = 24887617 | doi = 10.7326/M13-1467 | doi-access = free }} Rate control lowers the heart rate closer to normal, usually 60 to 100 bpm, without trying to convert to a regular rhythm. Rhythm control tries to restore a normal heart rhythm in a process called cardioversion and maintains the normal rhythm with medications. Studies suggest that rhythm control is more important in the acute setting AF, whereas rate control is more important in the long-term.

The risk of stroke appears to be lower with rate control versus attempted rhythm control, at least in those with heart failure.{{cite journal | vauthors = Frankel G, Kamrul R, Kosar L, Jensen B | title = Rate versus rhythm control in atrial fibrillation | journal = Canadian Family Physician | volume = 59 | issue = 2 | pages = 161–168 | date = February 2013 | pmid = 23418244 | pmc = 3576947 }} AF is associated with a reduced quality of life, and, while some studies indicate that rhythm control leads to a higher quality of life, some did not find a difference.{{cite journal | vauthors = Thrall G, Lane D, Carroll D, Lip GY | title = Quality of life in patients with atrial fibrillation: a systematic review | journal = The American Journal of Medicine | volume = 119 | issue = 5 | pages = 448.e1–448.19 | date = May 2006 | pmid = 16651058 | doi = 10.1016/j.amjmed.2005.10.057 | doi-access = free }} Neither rate nor rhythm control is superior in people with heart failure when they are compared in various clinical trials. However, rate control is recommended as the first-line treatment regimen for people with heart failure. On the other hand, rhythm control is only recommended when people experience persistent symptoms despite adequate rate control therapy.{{cite journal | vauthors = Trulock KM, Narayan SM, Piccini JP | title = Rhythm control in heart failure patients with atrial fibrillation: contemporary challenges including the role of ablation | journal = Journal of the American College of Cardiology | volume = 64 | issue = 7 | pages = 710–721 | date = August 2014 | pmid = 25125304 | doi = 10.1016/j.jacc.2014.06.1169 | quote = Multiple studies have compared pharmacological rate and rhythm strategies but have failed to identify a superior therapy, a finding that extends to patients with HF. ... Antiarrhythmic drug therapy is indicated as first-line therapy for AF that remains symptomatic despite adequate rate control. | doi-access = free }}

In those with a fast ventricular response, intravenous magnesium significantly increases the chances of achieving successful rate and rhythm control in the urgent setting without major side-effects.{{cite journal | vauthors = Onalan O, Crystal E, Daoulah A, Lau C, Crystal A, Lashevsky I | title = Meta-analysis of magnesium therapy for the acute management of rapid atrial fibrillation | journal = The American Journal of Cardiology | volume = 99 | issue = 12 | pages = 1726–1732 | date = June 2007 | pmid = 17560883 | doi = 10.1016/j.amjcard.2007.01.057 }} A person with poor vital signs, mental status changes, preexcitation, or chest pain often will go to immediate treatment with synchronized direct current cardioversion. Otherwise, the decision of rate control versus rhythm control using medications is made. This is based on several criteria that include whether or not symptoms persist with rate control.

Rate control to a target heart rate of fewer than 110 beats per minute is recommended in most people. Lower heart rates may be recommended in those with left ventricular hypertrophy or reduced left ventricular function.{{cite journal | vauthors = Badheka AO, Shah N, Grover PM, Patel NJ, Chothani A, Mehta K, Singh V, Deshmukh A, Savani GT, Rathod A, Panaich SS, Patel N, Arora S, Bhalara V, Coffey JO, Mitrani RD, Halperin JL, Viles-Gonzalez JF | title = Outcomes in atrial fibrillation patients with and without left ventricular hypertrophy when treated with a lenient rate-control or rhythm-control strategy | journal = The American Journal of Cardiology | volume = 113 | issue = 7 | pages = 1159–1165 | date = April 2014 | pmid = 24507168 | doi = 10.1016/j.amjcard.2013.12.021 }} Rate control is achieved with medications that work by increasing the degree of the block at the level of the AV node, decreasing the number of impulses that conduct into the ventricles. This can be done with:{{Cite web |title=Atrial fibrillation: diagnosis and management |url=https://www.nice.org.uk/guidance/ng196 |date=27 April 2021 |access-date=16 March 2025 |website=National Institute for Health and Care Excellence}}

• Beta blockers (preferably the "cardioselective" beta blockers such as metoprolol, bisoprolol, or nebivolol)
• Non-dihydropyridine calcium channel blockers (e.g., diltiazem or verapamil)
• Cardiac glycosides (e.g., digoxin) – have less use, apart from in older people who are sedentary. They are not as effective as either beta-blockers or calcium channel blockers.

In addition to these agents, amiodarone has some AV node blocking effects (in particular when administered intravenously) and can be used in individuals when other agents are contraindicated or ineffective (particularly due to hypotension).

Cardioversion is the attempt to switch an irregular heartbeat to a normal heartbeat using electrical or chemical means.

• Electrical cardioversion involves the restoration of normal heart rhythm through the application of a direct current electrical shock. The exact placement of the pads does not appear to be important.{{cite journal | vauthors = Kirkland S, Stiell I, AlShawabkeh T, Campbell S, Dickinson G, Rowe BH | title = The efficacy of pad placement for electrical cardioversion of atrial fibrillation/flutter: a systematic review | journal = Academic Emergency Medicine | volume = 21 | issue = 7 | pages = 717–726 | date = July 2014 | pmid = 25117151 | doi = 10.1111/acem.12407 | s2cid = 36859521 | doi-access = free }}
• Chemical cardioversion is performed with medications, such as amiodarone, dronedarone,{{cite journal | vauthors = Singh BN, Connolly SJ, Crijns HJ, Roy D, Kowey PR, Capucci A, Radzik D, Aliot EM, Hohnloser SH | title = Dronedarone for maintenance of sinus rhythm in atrial fibrillation or flutter | journal = The New England Journal of Medicine | volume = 357 | issue = 10 | pages = 987–999 | date = September 2007 | pmid = 17804843 | doi = 10.1056/NEJMoa054686 | hdl-access = free | s2cid = 9264507 | hdl = 11566/54713 }} procainamide (especially in pre-excited atrial fibrillation), dofetilide, ibutilide, propafenone, or flecainide.

After successful cardioversion, the heart may be stunned, which means that there is a normal rhythm, but the restoration of normal atrial contraction has not yet occurred.{{cite journal | vauthors = Watson T, Shantsila E, Lip GY | title = Mechanisms of thrombogenesis in atrial fibrillation: Virchow's triad revisited | journal = Lancet | volume = 373 | issue = 9658 | pages = 155–166 | date = January 2009 | pmid = 19135613 | doi = 10.1016/S0140-6736(09)60040-4 | s2cid = 35178625 }}

Catheter ablation (CA) is a procedure performed by an electrophysiologist, a cardiologist who specializes in heart rhythm problems, to restore the heart's normal rhythm by destroying, or electrically isolating, specific parts of the atria. A group of cardiologists led by Dr Haïssaguerre from {{ill|Bordeaux University Hospital|fr|Centre hospitalier universitaire de Bordeaux}} noted in 1998 that the pulmonary veins are an important source of ectopic beats, initiating frequent paroxysms of atrial fibrillation, with these foci responding to treatment with radio-frequency ablation.{{cite journal | vauthors = Haïssaguerre M, Jaïs P, Shah DC, Takahashi A, Hocini M, Quiniou G, Garrigue S, Le Mouroux A, Le Métayer P, Clémenty J | title = Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins | journal = The New England Journal of Medicine | volume = 339 | issue = 10 | pages = 659–666 | date = September 1998 | pmid = 9725923 | doi = 10.1056/NEJM199809033391003 | doi-access = free }} Most commonly, CA electrically isolates the left atrium from the pulmonary veins, where most of the abnormal electrical activity promoting atrial fibrillation originates. CA is a form of rhythm control that restores normal sinus rhythm and reduces AF-associated symptoms more reliably than antiarrhythmic medications.

Electrophysiologists generally use three forms of catheter ablation: radiofrequency (RF) ablation, cryoablation ("cryo"), or pulsed field (PF).{{citation needed|date=March 2025}} In young people with little-to-no structural heart disease where rhythm control is desired and cannot be maintained by medication or cardioversion, ablation may be attempted and may be preferred over several years of medical therapy.{{cite journal | vauthors = Leong-Sit P, Zado E, Callans DJ, Garcia F, Lin D, Dixit S, Bala R, Riley MP, Hutchinson MD, Cooper J, Gerstenfeld EP, Marchlinski FE | title = Efficacy and risk of atrial fibrillation ablation before 45 years of age | journal = Circulation: Arrhythmia and Electrophysiology | volume = 3 | issue = 5 | pages = 452–457 | date = October 2010 | pmid = 20858861 | doi = 10.1161/circep.110.938860 | doi-access = free }} Although radiofrequency ablation has become an accepted intervention in selected younger people and may be more effective than medication at improving symptoms and quality of life, there is no evidence that ablation reduces all-cause mortality, stroke, or heart failure.{{cite journal | vauthors = Upadhyay GA, Alenghat FJ | title = Catheter Ablation for Atrial Fibrillation in 2019 | journal = JAMA | volume = 322 | issue = 7 | pages = 686–687 | date = August 2019 | pmid = 31429886 | doi = 10.1001/jama.2019.10929 | s2cid = 201099189 }} Some evidence indicates CA may be particularly helpful for people with AF who also have heart failure.{{cite journal | vauthors = Vrachatis D, Deftereos S, Kekeris V, Tsoukala S, Giannopoulos G | title = Catheter Ablation for Atrial Fibrillation in Systolic Heart Failure Patients: Stone by Stone, a CASTLE | journal = Arrhythmia & Electrophysiology Review | volume = 7 | issue = 4 | pages = 265–272 | date = December 2018 | pmid = 30588315 | pmc = 6304798 | doi = 10.15420/aer.2018.41.2 }} AF may recur in people who have undergone CA and nearly half of people who undergo it will require a repeat procedure to achieve long-term control of their AF.

In general, CA is more successful at preventing AF recurrence if AF is paroxysmal as opposed to persistent.{{cite journal | vauthors = Scherr D, Khairy P, Miyazaki S, Aurillac-Lavignolle V, Pascale P, Wilton SB, Ramoul K, Komatsu Y, Roten L, Jadidi A, Linton N, Pedersen M, Daly M, O'Neill M, Knecht S, Weerasooriya R, Rostock T, Manninger M, Cochet H, Shah AJ, Yeim S, Denis A, Derval N, Hocini M, Sacher F, Haissaguerre M, Jais P | title = Five-year outcome of catheter ablation of persistent atrial fibrillation using termination of atrial fibrillation as a procedural endpoint | journal = Circulation: Arrhythmia and Electrophysiology | volume = 8 | issue = 1 | pages = 18–24 | date = February 2015 | pmid = 25528745 | doi = 10.1161/CIRCEP.114.001943 | doi-access = free }} As CA does not reduce the risk of stroke, many are advised to continue their anticoagulation. Possible complications include common, minor complications such as the formation of a collection of blood at the site where the catheter goes into the vein (access site hematoma), but also more dangerous complications including bleeding around the heart (cardiac tamponade), stroke, damage to the esophagus (atrio-esophageal fistula), or even death.{{cite journal | vauthors = Han HC, Ha FJ, Sanders P, Spencer R, Teh AW, O'Donnell D, Farouque O, Lim HS | title = Atrioesophageal Fistula: Clinical Presentation, Procedural Characteristics, Diagnostic Investigations, and Treatment Outcomes | journal = Circulation: Arrhythmia and Electrophysiology | volume = 10 | issue = 11 | pages = e005579 | date = November 2017 | pmid = 29109075 | doi = 10.1161/CIRCEP.117.005579 | s2cid = 20081569 | doi-access = free }} Use of pulsed field ablation as a non-thermal method of inducing electroporation avoids damage to the phrenic nerve, esophagus, and blood vessels, while being at least as effective as thermal ablation methods.{{cite journal | vauthors=Matos CD, Hoyos C, Osorio J | title=Pulsed Field Ablation of Atrial Fibrillation: A Comprehensive Review | journal= Reviews in Cardiovascular Medicine | volume=24 | issue=11 | pages=337 | year=2023 | doi = 10.31083/j.rcm2411337 | pmc=11272841 | pmid=39076426 }}

A hybrid convergent procedure has been developed which combines endocardial ablation with epicardial ablation, which can reduce AF recurrence to less than 5% for over one year.{{cite journal | vauthors=Larson J, Merchant FM, Westerman S | title=Outcomes of convergent atrial fibrillation ablation with continuous rhythm monitoring | journal=Journal of Cardiovascular Electrophysiology | volume=31 | issue=6 | pages=1270–1276 | year=2020 | doi=10.1111/jce.14454 | pmid=32219901 }} The epicardial ablation is performed first, with a minimally invasive surgical approach.{{cite journal | vauthors=DeLurgio DB, Gill JS, Halkos ME | title=Hybrid Convergent Procedure for the Treatment of Persistent and Long-standing Persistent Atrial Fibrillation | journal= Arrhythmia & Electrophysiology Review | volume=10 | issue=3 | pages=198–204 | year=2021 | doi = 10.15420/aer.2021.24 | pmc=8576514 | pmid=34777825 }}

An alternative to catheter ablation is surgical ablation. The maze procedure, first performed in 1987, is an effective invasive surgical treatment that is designed to create electrical blocks or barriers in the atria of the heart. The idea is to force abnormal electrical signals to move along one, uniform path to the lower chambers of the heart (ventricles), thus restoring the normal heart rhythm.Northwestern Surgery for Atrial Fibrillation. [http://www.nmh.org/nm/atrial-fibrillation-surgery Atrial Fibrillation Surgery] {{webarchive|url=https://web.archive.org/web/20120419183842/http://www.nmh.org/nm/atrial-fibrillation-surgery |date=19 April 2012 }} People with AF often undergo cardiac surgery for other underlying reasons and are frequently offered concomitant AF surgery to reduce the frequency of short- and long-term AF. Concomitant AF surgery is more likely to lead to the person being free from atrial fibrillation and off medications long-term after surgery and Cox-Maze IV procedure is the gold standard treatment. There is a slightly increased risk of needing a pacemaker following the procedure.{{cite journal | vauthors = Huffman MD, Karmali KN, Berendsen MA, Andrei AC, Kruse J, McCarthy PM, Malaisrie SC | title = Concomitant atrial fibrillation surgery for people undergoing cardiac surgery | journal = The Cochrane Database of Systematic Reviews | volume = 2016 | issue = 8 | pages = CD011814 | date = August 2016 | pmid = 27551927 | pmc = 5046840 | doi = 10.1002/14651858.CD011814.pub2 | collaboration = Cochrane Heart Group }}{{cite journal | vauthors = Blackstone EH, Chang HL, Rajeswaran J, Parides MK, Ishwaran H, Li L, Ehrlinger J, Gelijns AC, Moskowitz AJ, Argenziano M, DeRose JJ, Couderc JP, Balda D, Dagenais F, Mack MJ, Ailawadi G, Smith PK, Acker MA, O'Gara PT, Gillinov AM | title = Biatrial maze procedure versus pulmonary vein isolation for atrial fibrillation during mitral valve surgery: New analytical approaches and end points | journal = The Journal of Thoracic and Cardiovascular Surgery | volume = 157 | issue = 1 | pages = 234–243.e9 | date = January 2019 | pmid = 30557941 | pmc = 6486838 | doi = 10.1016/j.jtcvs.2018.06.093 | s2cid = 56176611 }}{{cite journal | vauthors = Sef D, Trkulja V, Raja SG, Hooper J, Turina MI | title = Comparing mid-term outcomes of Cox-Maze procedure and pulmonary vein isolation for atrial fibrillation after concomitant mitral valve surgery: A systematic review | journal = Journal of Cardiac Surgery | volume = 37 | issue = 11 | pages = 3801–3810 | date = November 2022 | pmid = 36040710 | pmc = 9804989 | doi = 10.1111/jocs.16888 | s2cid = 251932594 }} Less invasive modifications of the maze procedure have been developed, designated as minimaze procedures.

There is growing evidence that left atrial appendage occlusion therapy may reduce the risk of stroke in people with non-valvular AF as much as warfarin.{{cite journal | vauthors = Zhou X, Zhang W, Lv W, Zhou Q, Li Y, Zhang L, Lu Y, Zhang J, Xing Q, Wang H, Tang B | title = Left atrial appendage occlusion in atrial fibrillation for stroke prevention: A systemic review | journal = International Journal of Cardiology | volume = 203 | pages = 55–59 | date = January 2016 | pmid = 26492310 | doi = 10.1016/j.ijcard.2015.10.011 }}{{cite journal | vauthors = Glikson M, Wolff R, Hindricks G, Mandrola J, Camm AJ, Lip GY, Fauchier L, Betts TR, Lewalter T, Saw J, Tzikas A, Sternik L, Nietlispach F, Berti S, Sievert H, Bertog S, Meier B | title = EHRA/EAPCI expert consensus statement on catheter-based left atrial appendage occlusion - an update | journal = EuroIntervention | volume = 15 | issue = 13 | pages = 1133–1180 | date = January 2020 | pmid = 31474583 | doi = 10.4244/EIJY19M08_01 | s2cid = 201717267 | doi-access = free }} The addition of left atrial appendage isolation to catheter ablation has reduced AF recurrence by 80% in patients with persistent AF.{{cite journal | vauthors=AlTurki A, Huynh T, Essebag V | title=Left atrial appendage isolation in atrial fibrillation catheter ablation: A meta-analysis | journal= Journal of Arrhythmia | volume=34 | issue=5 | pages=478–484 | year=2018| doi = 10.1002/joa3.12095 | pmc=6174377 | pmid=30327692 }}

File:3D Medical Animation of Left Atrial Appendage Occlusion.jpg

After catheter ablation, people are moved to a cardiac recovery unit, intensive care unit, or cardiovascular intensive care unit where they are not allowed to move for 4{{ndash}}6 hours. Minimizing movement helps prevent bleeding from the site of the catheter insertion. The length of time people stay in the hospital varies from hours to days. This depends on the problem, the length of the operation, and whether or not general anesthetic was used. Additionally, people should not engage in strenuous physical activity{{snd}}to maintain a low heart rate and low blood pressure{{snd}}for around six weeks.

AF often occurs after cardiac surgery and is usually self-limiting. It is strongly associated with age, preoperative hypertension, and the number of vessels grafted. Measures should be taken to control hypertension preoperatively to reduce the risk of AF. Also, people with a higher risk of AF, e.g., people with pre-operative hypertension, more than three vessels grafted, or greater than 70 years of age, should be considered for prophylactic treatment. Postoperative pericardial effusion is also suspected to be the cause of atrial fibrillation. Prophylaxis may include prophylactic postoperative rate and rhythm management. Some authors perform posterior pericardiotomy to reduce the incidence of postoperative AF.{{cite journal | vauthors = Kaleda VI, McCormack DJ, Shipolini AR | title = Does posterior pericardiotomy reduce the incidence of atrial fibrillation after coronary artery bypass grafting surgery? | journal = Interactive Cardiovascular and Thoracic Surgery | volume = 14 | issue = 4 | pages = 384–389 | date = April 2012 | pmid = 22235005 | pmc = 3309809 | doi = 10.1093/icvts/ivr099 }} When AF occurs, management should primarily be rate and rhythm control. However, cardioversion may be used if the patient is hemodynamically unstable, highly symptomatic, or AF persists for six weeks after discharge. In persistent cases, anticoagulation should be used.

Atrial fibrillation can progress from infrequent occurrences to more frequent occurrences, ultimately becoming permanent.{{cite journal | vauthors = Wijesurendra RS, Casadei B | title = Mechanisms of atrial fibrillation | journal = Heart | volume = 105 | issue = 24 | pages = 1860–1867 | date = December 2019 | pmid = 31444267 | doi = 10.1136/heartjnl-2018-314267 | s2cid = 201631227 | url = https://ora.ox.ac.uk/objects/uuid:cefada22-60a7-4382-8294-a1cd939ed674 }} Some cases do not progress, especially among patients with a healthy lifestyle.{{cite journal | vauthors = Blum S, Aeschbacher S, Meyre P, Zwimpfer L, Reichlin T, Beer JH, Ammann P, Auricchio A, Kobza R, Erne P, Moschovitis G, Di Valentino M, Shah D, Schläpfer J, Henz S, Meyer-Zürn C, Roten L, Schwenkglenks M, Sticherling C, Kühne M, Osswald S, Conen D | title = Incidence and Predictors of Atrial Fibrillation Progression | journal = Journal of the American Heart Association | volume = 8 | issue = 20 | pages = e012554 | date = October 2019 | pmid = 31590581 | pmc = 6818023 | doi = 10.1161/JAHA.119.012554 }}

Many mechanisms contribute to cardiac remodeling leading to a worsening of atrial fibrillation, including fibrosis, fatty infiltration, amyloidosis, and ion channel modifications.{{cite journal | vauthors=Calkins H, Hindricks G, Yamane T | title=2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation | journal=Europace | volume=20 | issue=1 | pages=e1–e160 | year=2018 | doi = 10.1093/europace/eux274 | pmc=5834122 | pmid=29016840 }} Fatty infiltration helps explain why obesity is a risk factor for atrial fibrillation in one fifth of patients.

Atrial fibrillation increases the risk of heart failure by 11 per 1000, kidney problems by 6 per 1000, death by 4 per 1000, stroke by 3 per 1000, and coronary heart disease by 1 per 1000.{{cite journal | vauthors = Odutayo A, Wong CX, Hsiao AJ, Hopewell S, Altman DG, Emdin CA | title = Atrial fibrillation and risks of cardiovascular disease, renal disease, and death: systematic review and meta-analysis | journal = BMJ | volume = 354 | pages = i4482 | date = September 2016 | pmid = 27599725 | doi = 10.1136/bmj.i4482 | s2cid = 7881115 | doi-access = free | hdl = 1721.1/108109 | hdl-access = free }} Women have a worse outcome overall than men.{{cite journal | vauthors = Emdin CA, Wong CX, Hsiao AJ, Altman DG, Peters SA, Woodward M, Odutayo AA | title = Atrial fibrillation as risk factor for cardiovascular disease and death in women compared with men: systematic review and meta-analysis of cohort studies | journal = BMJ | volume = 532 | pages = h7013 | date = January 2016 | pmid = 26786546 | pmc = 5482349 | doi = 10.1136/bmj.h7013 }} Evidence increasingly suggests that atrial fibrillation is independently associated with a higher risk of developing dementia.{{cite journal | vauthors = Rivard L, Khairy P | title = Mechanisms, Clinical Significance, and Prevention of Cognitive Impairment in Patients With Atrial Fibrillation | journal = The Canadian Journal of Cardiology | volume = 33 | issue = 12 | pages = 1556–1564 | date = December 2017 | pmid = 29173598 | doi = 10.1016/j.cjca.2017.09.024 | type = Review | doi-access = free }}

Determining the risk of an embolism causing a stroke is important for guiding the use of anticoagulants. The most accurate clinical prediction rules is the CHA₂DS₂-VASc score.Lopes RD, Crowley MJ, Shah BR, et al. Stroke Prevention in Atrial Fibrillation. Comparative Effectiveness Review No. 123. AHRQ Publication No. 13-EHC113-EF. Rockville, MD: Agency for Healthcare Research and Quality; August 2013. www.effectivehealthcare.ahrq.gov/ reports/final.cfm. The addition of blood based biomarkers such as NT-proBNP and neurofilament light chain improves risk prediction significantly.{{Cite journal |last1=Aulin |first1=Julia |last2=Sjölin |first2=Karl |last3=Lindbäck |first3=Johan |last4=Benz |first4=Alexander P. |last5=Eikelboom |first5=John W. |last6=Hijazi |first6=Ziad |last7=Kultima |first7=Kim |last8=Oldgren |first8=Jonas |last9=Wallentin |first9=Lars |last10=Burman |first10=Joachim |last11=on behalf of the ACTIVE A and AVERROES Investigators |date=2024-07-24 |title=Neurofilament Light Chain and Risk of Stroke in Patients With Atrial Fibrillation |url=https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.124.069440 |journal=Circulation |volume=150 |issue=14 |pages=1090–1100 |language=en |doi=10.1161/CIRCULATIONAHA.124.069440 |pmid=39045686 |issn=0009-7322|url-access=subscription }} A CHA₂DS₂-VASc score of zero is considered very low risk.{{cite journal | vauthors = Olesen JB, Torp-Pedersen C, Hansen ML, Lip GY | title = The value of the CHA2DS2-VASc score for refining stroke risk stratification in patients with atrial fibrillation with a CHADS2 score 0-1: a nationwide cohort study | journal = Thrombosis and Haemostasis | volume = 107 | issue = 6 | pages = 1172–1179 | date = June 2012 | pmid = 22473219 | doi = 10.1160/th12-03-0175 | s2cid = 10318035 }}

In atrial fibrillation, the lack of an organized atrial contraction can result in some stagnant blood in the left atrium (LA) or left atrial appendage (LAA). This lack of movement of blood can lead to thrombus formation (blood clotting). If the clot becomes mobile and is carried away by the blood circulation, it is called an embolus. An embolus proceeds through smaller and smaller arteries until it plugs one of them and prevents blood from flowing through the artery. This process results in end organ damage due to the loss of nutrients, oxygen, and the removal of cellular waste products. Emboli in the brain may result in an ischemic stroke or a transient ischemic attack (TIA).

More than 90% of cases of thrombi associated with non-valvular atrial fibrillation evolve in the left atrial appendage.{{cite journal | vauthors = Blackshear JL, Odell JA | title = Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation | journal = The Annals of Thoracic Surgery | volume = 61 | issue = 2 | pages = 755–759 | date = February 1996 | pmid = 8572814 | doi = 10.1016/0003-4975(95)00887-X | doi-access = free }} However, the LAA lies in close relation to the free wall of the left ventricle, and thus the LAA's emptying and filling, which determines its degree of blood stagnation, may be helped by the motion of the wall of the left ventricle if there is good ventricular function.{{cite journal | vauthors = Al-Saady NM, Obel OA, Camm AJ | title = Left atrial appendage: structure, function, and role in thromboembolism | journal = Heart | volume = 82 | issue = 5 | pages = 547–554 | date = November 1999 | pmid = 10525506 | pmc = 1760793 | doi = 10.1136/hrt.82.5.547 }}

Atrial fibrillation has been independently associated with a higher risk of developing cognitive impairment, vascular dementia, and Alzheimer disease and with elevated levels of neurofilament light chain in blood, a biomarker indicating neuroaxonal injury.{{cite journal | vauthors = Sjölin K, Aulin J, Wallentin L, Eriksson N, Held C, Kultima K, Oldgren J, Burman J | title = Serum Neurofilament Light Chain in Patients With Atrial Fibrillation | journal = Journal of the American Heart Association | volume = 11 | issue = 14 | pages = e025910 | date = July 2022 | pmid = 35861814 | pmc = 9707825 | doi = 10.1161/JAHA.122.025910 | doi-access = free }}{{cite journal | vauthors = Diener HC, Hart RG, Koudstaal PJ, Lane DA, Lip GY | title = Atrial Fibrillation and Cognitive Function: JACC Review Topic of the Week | journal = Journal of the American College of Cardiology | volume = 73 | issue = 5 | pages = 612–619 | date = February 2019 | pmid = 30732716 | doi = 10.1016/j.jacc.2018.10.077 | doi-access = free }} Several mechanisms for this association have been proposed, including silent small blood clots (subclinical microthrombi) traveling to the brain resulting in small ischemic strokes without symptoms, altered blood flow to the brain, inflammation, clinically silent small bleeds in the brain, and genetic factors.{{cite journal | vauthors = Madhavan M, Graff-Radford J, Piccini JP, Gersh BJ | title = Cognitive dysfunction in atrial fibrillation | journal = Nature Reviews. Cardiology | volume = 15 | issue = 12 | pages = 744–756 | date = December 2018 | pmid = 30275499 | doi = 10.1038/s41569-018-0075-z | s2cid = 52901769 }} Tentative evidence suggests that effective anticoagulation with direct oral anticoagulants or warfarin may be somewhat protective against AF-associated dementia and evidence of silent ischemic strokes on MRI but this remains an active area of investigation.

Atrial fibrillation is the most common arrhythmia and affects more than 33 million people worldwide. In Europe and North America, {{as of|2014|lc=on}}, it affects about 2% to 3% of the population. In the developing world, rates are about 0.6% for males and 0.4% for females. The number of people diagnosed with AF has increased due to better detection of silent AF, increasing age and increase of conditions that predispose to it such as obesity and increasing survival from other forms of cardiovascular disease.

The rate of hospital admissions for AF has risen.{{cite journal | vauthors = Friberg J, Buch P, Scharling H, Gadsbphioll N, Jensen GB | title = Rising rates of hospital admissions for atrial fibrillation | journal = Epidemiology | volume = 14 | issue = 6 | pages = 666–672 | date = November 2003 | pmid = 14569181 | doi = 10.1097/01.ede.0000091649.26364.c0 | s2cid = 19079630 | doi-access = free }} AF is the cause for 20% of all ischemic strokes. After a transient ischemic attack or stroke, about 11% are found to have a new diagnosis of atrial fibrillation.{{cite journal | vauthors = Kishore A, Vail A, Majid A, Dawson J, Lees KR, Tyrrell PJ, Smith CJ | title = Detection of atrial fibrillation after ischemic stroke or transient ischemic attack: a systematic review and meta-analysis | journal = Stroke | volume = 45 | issue = 2 | pages = 520–526 | date = February 2014 | pmid = 24385275 | doi = 10.1161/STROKEAHA.113.003433 | doi-access = free }} 3% to 11% of patients with AF have structurally normal hearts.{{cite journal | vauthors = Sanfilippo AJ, Abascal VM, Sheehan M, Oertel LB, Harrigan P, Hughes RA, Weyman AE | title = Atrial enlargement as a consequence of atrial fibrillation. A prospective echocardiographic study | journal = Circulation | volume = 82 | issue = 3 | pages = 792–797 | date = September 1990 | pmid = 2144217 | doi = 10.1161/01.CIR.82.3.792 | doi-access = free }}

The number of new cases each year of AF increases with age. In younger people the prevalence is estimated to be 0.05% and is associated with congenital heart disease or structural heart disease in this demographic.{{cite journal | vauthors = Gourraud JB, Khairy P, Abadir S, Tadros R, Cadrin-Tourigny J, Macle L, Dyrda K, Mondesert B, Dubuc M, Guerra PG, Thibault B, Roy D, Talajic M, Rivard L | title = Atrial fibrillation in young patients | journal = Expert Review of Cardiovascular Therapy | volume = 16 | issue = 7 | pages = 489–500 | date = July 2018 | pmid = 29912584 | doi = 10.1080/14779072.2018.1490644 | s2cid = 49305621 }} As of 2001, it was anticipated that in developed countries, the number of people with atrial fibrillation was likely to increase during the following 50 years, due to the growing proportion of elderly people.{{cite journal | vauthors = Go AS, Hylek EM, Phillips KA, Chang Y, Henault LE, Selby JV, Singer DE | title = Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Study | journal = JAMA | volume = 285 | issue = 18 | pages = 2370–2375 | date = May 2001 | pmid = 11343485 | doi = 10.1001/jama.285.18.2370 | doi-access = free | department = primary source }}

Atrial fibrillation is more common in men than in women when reviewed in European and North American populations.{{cite journal | vauthors = Schnabel RB, Yin X, Gona P, Larson MG, Beiser AS, McManus DD, Newton-Cheh C, Lubitz SA, Magnani JW, Ellinor PT, Seshadri S, Wolf PA, Vasan RS, Benjamin EJ, Levy D | title = 50 year trends in atrial fibrillation prevalence, incidence, risk factors, and mortality in the Framingham Heart Study: a cohort study | journal = Lancet | volume = 386 | issue = 9989 | pages = 154–162 | date = July 2015 | pmid = 25960110 | pmc = 4553037 | doi = 10.1016/S0140-6736(14)61774-8 }} In developed and developing countries, there is also a higher rate in men than in women. The risk factors associated with AF are also distributed differently according to gender. In men, coronary disease is more frequent, while in women, high systolic blood pressure and valvular heart disease are more prevalent.

Rates of AF are lower in populations of African descent than in populations of European descent. African descent is associated with a protective effect for AF, due to the lower presence of SNPs with guanine alleles. European ancestry has more frequent mutations. The variant rs4611994 for the gene PITX2 is associated with risk of AF in African and European populations. Hispanic and Asian populations have a lower risk of AF than European populations. The risk of AF in non-European populations is associated with characteristic risk factors of these populations, such as hypertension.{{cite journal | vauthors = Dewland TA, Olgin JE, Vittinghoff E, Marcus GM | title = Incident atrial fibrillation among Asians, Hispanics, blacks, and whites | journal = Circulation | volume = 128 | issue = 23 | pages = 2470–2477 | date = December 2013 | pmid = 24103419 | doi = 10.1161/CIRCULATIONAHA.113.002449 | doi-access = free }}

Atrial fibrillation is an uncommon condition in children but sometimes occurs in association with certain inherited and acquired conditions. Congenital heart disease and rheumatic fever are the most common causes of atrial fibrillation in children. Other inherited heart conditions associated with the development of atrial fibrillation in children include Brugada syndrome, short QT syndrome, Wolff Parkinson White syndrome, and other forms of supraventricular tachycardia (e.g., AV nodal reentrant tachycardia). Adults who survived congenital heart disease have an increased risk of developing AF. In particular, people who had atrial septal defects, Tetralogy of Fallot, or Ebstein's anomaly, and those who underwent the Fontan procedure, are at higher risk with prevalence rates of up to 30% depending on the heart's anatomy and the person's age.

Because the diagnosis of atrial fibrillation requires measurement of the electrical activity of the heart, atrial fibrillation was not truly described until 1874, when Edmé Félix Alfred Vulpian observed the irregular atrial electrical behavior that he termed "fremissement fibrillaire" in dog hearts.{{cite journal | vauthors = Vulpian A |year = 1874 |title = Note sur les effets de la faradisation directe des ventricules du coeur chez le chien |journal = Archives de Physiologie Normale et Pathologique |volume = 6 |page = 975 }} In the mid-18th century, Jean-Baptiste de Sénac made note of dilated, irritated atria in people with mitral stenosis.{{cite journal | vauthors = McMichael J | title = History of atrial fibrillation 1628-1819 Harvey - de Senac - Laënnec | journal = British Heart Journal | volume = 48 | issue = 3 | pages = 193–197 | date = September 1982 | pmid = 7049202 | pmc = 481228 | doi = 10.1136/hrt.48.3.193 }} The irregular pulse associated with AF was first recorded in 1876 by Carl Wilhelm Hermann Nothnagel and termed "delirium cordis", stating that "[I]n this form of arrhythmia the heartbeats follow each other in complete irregularity. At the same time, the height and tension of the individual pulse waves are continuously changing".{{cite journal | vauthors = Nothnagel H |year = 1876 |title = Ueber arythmische Herzthatigkeit |journal = Deutsches Archiv für Klinische Medizin |volume = 17 |pages = 190–220 }} Correlation of delirium cordis with the loss of atrial contraction, as reflected in the loss of a waves in the jugular venous pulse, was made by Sir James MacKenzie in 1904.{{cite journal | vauthors = Mackenzie J | title = Observations on the Inception of the Rhythm of the Heart by the Ventricle: As the cause of Continuous Irregularity of the Heart | journal = British Medical Journal | volume = 1 | issue = 2253 | pages = 529–536 | date = March 1904 | pmid = 20761393 | pmc = 2353402 | doi = 10.1136/bmj.1.2253.529 }} Willem Einthoven published the first ECG showing AF in 1906.{{cite journal | vauthors = Einthoven W |year = 1906 |title = Le telecardiogramme |journal = Archives Internationales de Physiologie |volume = 4 |pages = 132–64 }} The connection between the anatomic and electrical manifestations of AF and the irregular pulse of delirium cordis was made in 1909 by Carl Julius Rothberger, Heinrich Winterberg, and Sir Thomas Lewis.{{cite journal | vauthors = Rothberger CJ, Winterberg H |year = 1909 |title = Vorhofflimmern und Arhythmia perpetua |journal = Wiener Klinische Wochenschrift |volume = 22 |pages = 839–44 }}{{cite journal | vauthors = Lewis T | title = Report CXIX. Auricular fibrillation: a common clinical condition | journal = British Medical Journal | volume = 2 | issue = 2552 | page = 1528 | date = November 1909 | pmid = 20764769 | pmc = 2321318 | doi = 10.1136/bmj.2.2552.1528 }}{{cite journal | vauthors = Flegel KM | title = From delirium cordis to atrial fibrillation: historical development of a disease concept | journal = Annals of Internal Medicine | volume = 122 | issue = 11 | pages = 867–873 | date = June 1995 | pmid = 7741373 | doi = 10.7326/0003-4819-122-11-199506010-00010 | s2cid = 10629315 }}

Atrial fibrillation occurs in other animals, including cats, dogs, and horses.{{cite journal | vauthors = Pariaut R | title = Atrial Fibrillation: Current Therapies | journal = The Veterinary Clinics of North America. Small Animal Practice | volume = 47 | issue = 5 | pages = 977–988 | date = September 2017 | pmid = 28645513 | doi = 10.1016/j.cvsm.2017.04.002 }}{{cite journal | vauthors = van Loon G | title = Cardiac Arrhythmias in Horses | journal = The Veterinary Clinics of North America. Equine Practice | volume = 35 | issue = 1 | pages = 85–102 | date = April 2019 | pmid = 30871832 | doi = 10.1016/j.cveq.2018.12.004 | s2cid = 78092141 }} Unlike humans, dogs rarely develop the complications that stem from blood clots breaking off from inside the heart and traveling through the arteries to distant sites (thromboembolic complications). Cats rarely develop atrial fibrillation but appear to have a higher risk of thromboembolic complications than dogs.

Cats and dogs with atrial fibrillation often have underlying structural heart disease that predisposes them to the condition. The medications used in animals for atrial fibrillation are largely similar to those used in humans. Electrical cardioversion is occasionally performed in these animals, but the need for general anesthesia limits its use. Standardbred horses appear to be genetically susceptible to developing atrial fibrillation. Horses that develop atrial fibrillation often have minimal or no underlying heart disease, and the presence of atrial fibrillation in horses can adversely affect physical performance.

{{Reflist}}

• {{Cite journal |vauthors= Van Gelder IC, Rienstra M, Bunting KV, Casado-Arroyo R, Caso V, Crijns HJ, De Potter TJ, Dwight J, Guasti L, Hanke T, Jaarsma T, Lettino M, Løchen ML, Lumbers RT, Maesen B, Mølgaard I, Rosano GM, Sanders P, Schnabel RB, Suwalski P, Svennberg E, Tamargo J, Tica O, Traykov V, Tzeis S, Kotecha D |date=30 August 2024 |title=2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS) |journal=European Heart Journal |volume=45 |issue=36 |pages=3314–3414 |doi=10.1093/eurheartj/ehae176 |doi-access=free |pmid=39210723 |issn=0195-668X|hdl=11392/2573658 |hdl-access=free }}

• {{Cite journal |vauthors= Joglar JA, Chung MK, Armbruster AL, Benjamin EJ, Chyou JY, Cronin EM, Deswal A, Eckhardt LL, Goldberger ZD, Gopinathannair R, Gorenek B, Hess PL, Hlatky MH, Hogan G, Ibeh C, Indik JH, Kido K, Kusumoto F, Link MS, Linta KT, Marcus GM, McCarthy PM, Patel N, Patton KK, Perez MV, Piccini JP, Russo AM, Sanders P, Streur MM, Thomas KL, Times S, Tisdale JE, Valente AM, Van Wagoner DR |date=30 November 2023 |title=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 |journal=Circulation |language=en |volume=149 |issue=1 |pages=e1–e156 |doi=10.1161/CIR.0000000000001193 |doi-access=free |pmc=11095842 |pmid=38033089}}

• {{cite web |title=Atrial Fibrillation |url=https://world-heart-federation.org/cvd-roadmaps/whf-global-roadmaps/atrial-fibrillation/ |website=CVD Roadmaps |publisher=World Heart Federation}}
• {{commons category-inline}}

{{Medical condition classification and resources

| DiseasesDB = 1065

| ICD10 = {{ICD10|I48.0}}, {{ICD10|I48.1}}, {{ICD10|I48.2}}, {{ICD10|I48.9}}

| ICD9 = {{ICD9|427.31}}

| ICDO =

| OMIM =

| MedlinePlus = 000184

| eMedicineSubj = article

| eMedicineTopic = 151066

| eMedicine_mult = {{eMedicine2|emerg|46}}

| MeshID = D001281

}}

{{Circulatory system pathology}}

{{Authority control}}

Category:Cardiac arrhythmia

Category:Wikipedia emergency medicine articles ready to translate

Category:Wikipedia medicine articles ready to translate