Atrial FibrillationEdit

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults. It arises from disorganized electrical activity in the atria, which leads to an irregular and often rapid ventricular response. The condition increases the risk of stroke and heart failure, and it requires a careful balance of treatments aimed at preventing clotting, controlling heart rate, and, when appropriate, restoring normal rhythm. AF typically reflects a mix of aging, cardiovascular risk factors, and structural heart disease, but it is also influenced by lifestyle factors that people can reasonably modify.

AF is heterogeneous in presentation and course. Some people experience sudden episodes that come and go (paroxysmal AF), while others have persistent arrhythmias that require treatment to regain normal rhythm, and a subset remains in continuous AF (long-standing persistent or permanent AF). The clinical approach emphasizes individualized assessment and shared decision-making, with attention to stroke risk, bleeding risk, symptom burden, comorbidities, and life expectancy. atrial fibrillation stroke anticoagulation catheter ablation left atrial appendage occlusion

Epidemiology and risk factors

AF affects millions worldwide and becomes more common with age. In most populations, the condition is driven by a combination of risk factors, including high blood pressure, obesity, diabetes, heart failure, and valvular heart disease. Sleep apnea and excessive alcohol use can precipitate AF or worsen its persistence. Other contributors include ischemic heart disease, prior cardiac surgery, and certain genetic predispositions. The distribution of AF varies with socioeconomic and healthcare access factors, but the underlying biology—atrial remodeling and triggers from the pulmonary veins—remains consistent. hypertension sleep apnea obesity diabetes mellitus heart failure valvular heart disease

Pathophysiology

AF begins with abnormal electrical impulses that disrupt the normal coordinated atrial contraction. Ectopic activity from the pulmonary veins often serves as a trigger, while ongoing inflammation, autonomic tone, and atrial structural changes promote perpetuation of the rhythm disturbance. The chaotic atrial activity reduces the heart’s efficiency and creates turbulence that can foster thrombus formation, particularly in the left atrial appendage. Over time, AF can lead to atrial remodeling that makes the arrhythmia harder to treat. For a deeper look at the electrical mechanisms and anatomical substrates, see electrophysiology and left atrial appendage.

Clinical features and diagnosis

AF can present with noticeable palpitations, lightheadedness, shortness of breath, or fatigue, especially during activity. Some people, however, have few or no symptoms, and AF is detected incidentally on routine testing. The hallmark on an electrocardiogram (ECG) is an irregularly irregular rhythm with the absence of discrete P waves. Diagnosis typically involves a brief ECG in the clinic, followed by longer-term rhythm monitoring if AF is suspected or symptoms persist. Echocardiography is often performed to assess heart structure and function and to guide management decisions. electrocardiogram echocardiography tachyarrhythmia

Risk assessment and prognosis

stroke risk assessment is central to AF management. The CHA2DS2-VASc score guides decisions about anticoagulation, balancing stroke prevention against bleeding risk. A higher score increases the net benefit of anticoagulation, even when AF symptoms are mild or intermittent. Other prognostic considerations include the patient’s age, heart function, and presence of other cardiovascular diseases. Anticoagulation reduces the risk of ischemic stroke but introduces bleeding risk, so individualization is essential. CHA2DS2-VASc score anticoagulation stroke

Management overview

Management of AF has three core aims: prevent stroke, control heart rate, and decide whether restoring or maintaining normal rhythm is desirable. In some patients, addressing underlying conditions (e.g., hypertension, sleep apnea, obesity) can markedly improve AF control and reduce recurrence.

Stroke prevention: For most patients, long-term anticoagulation is recommended based on stroke risk, with options including direct oral anticoagulants (direct oral anticoagulants such as apixaban, rivaroxaban, dabigatran, edoxaban) or, in specific situations, warfarin. Mechanical heart valves or certain kinds of valve disease generally require warfarin. The choice depends on bleeding risk, patient preferences, kidney function, and drug interactions. anticoagulation warfarin DOACs
Rate control: When AF is present, slowing the heart rate helps improve symptoms and reduce myocardial oxygen demand. Medications like beta-blockers and non-dihydropyridine calcium channel blockers are commonly used; digoxin may be added in selected cases, particularly when patients are sedentary. The goal is to relieve symptoms and preserve cardiac function without causing excessive bradycardia. beta-blockers calcium channel blockers digoxin
Rhythm control: Restoring and maintaining normal rhythm can improve quality of life for many patients. Options include electrical cardioversion, antiarrhythmic drugs (for example flecainide, propafenone, amiodarone, sotalol), and, in select patients, catheter-based ablation to isolate triggering sites in the pulmonary veins. Catheter ablation has become an important option for those who fail medical therapy or experience recurrent symptoms, with handheld success rates varying by patient characteristics. electrical cardioversion antiarrhythmic drugs catheter ablation pulmonary veins
Left atrial appendage occlusion: For patients who cannot tolerate long-term anticoagulation or have a high risk of bleeding, devices designed to occlude the left atrial appendage offer an alternative approach to reduce stroke risk. This is typically considered after careful evaluation of risks and benefits. left atrial appendage occlusion Watchman device (example device)
Lifestyle and risk-factor management: Weight management, regular physical activity, treatment of sleep apnea, and moderation of alcohol intake can reduce AF burden and improve response to other therapies. weight loss sleep apnea treatment exercise
Screening and follow-up: Ongoing monitoring for rhythm episodes and assessment of comorbid conditions helps tailor therapy over time. holter monitor ambulatory monitoring

Classifications and terminology

Paroxysmal AF: episodes that terminate spontaneously or with intervention within seven days.
Persistent AF: episodes that last longer than seven days or require intervention to terminate.
Long-standing persistent AF: continuous AF lasting more than one year when rhythm control strategies are pursued.
Permanent AF: AF that is accepted as a chronic condition, with rhythm control not pursued. These terms guide treatment planning and expectations. atrial fibrillation rhythm control rate control

Controversies and debates

Rhythm control vs. rate control: For years, physicians debated whether restoring normal rhythm improves outcomes beyond symptom relief. Early trials suggested similar hard outcomes between strategies, but recent studies such as EAST-AFNET 4 support earlier rhythm-control intervention in selected patients, showing potential reductions in cardiovascular events. Critics caution that rhythm-control strategies can carry procedure- and drug-related risks and may not benefit all patients equally. The choice depends on symptoms, comorbidities, and patient preferences. AFFIRM trial EAST-AFNET 4 trial
Anticoagulation decisions: The net benefit of anticoagulation hinges on stroke risk, bleeding risk, and patient values. Some patients with low scores may still experience strokes; others may avoid anticoagulation due to bleeding risk. Clinicians emphasize individualized decisions rather than a one-size-fits-all approach. The advent of DOACs offers options with different bleeding risk profiles compared with warfarin, but no anticoagulant is without risk. DOAC bleeding risk stroke prevention
Left atrial appendage occlusion: While LAA occlusion devices can reduce stroke risk in patients unsuitable for long-term anticoagulation, they are not universal solutions. They require expert procedural planning and long-term follow-up, and their cost-effectiveness depends on patient selection and healthcare system factors. left atrial appendage occlusion
Lifestyle interventions and public health: Weight reduction, treatment of sleep apnea, and other lifestyle changes can meaningfully reduce AF burden and improve outcomes, sometimes with modest cost relative to medication and procedures. Critics of over-medicalizing AF argue for stronger emphasis on risk-factor modification and patient empowerment, aiming for sustainable, evidence-based improvements rather than broad, one-size-fits-all campaigns. In practice, a pragmatic blend of medical therapy and targeted lifestyle change tends to work best. sleep apnea treatment weight loss exercise
Equity and access in treatment: Access to DOACs, ablation, and LAA occlusion varies by geography and health system structure. A fiscally conservative approach stresses ensuring resources are allocated to high-value therapies with proven benefit, while avoiding unnecessary or duplicative interventions. The focus remains on outcomes that meaningfully improve survival and quality of life without imposing excessive burdens on patients or the healthcare system. healthcare policy cost-effectiveness

Prognosis and long-term outcomes

AF is associated with an elevated risk of ischemic stroke, systemic embolism, and heart failure progression. The risk of stroke can be independent of symptom burden, which is why risk assessment and preventive therapy are central to management. With appropriate treatment, many patients experience improved symptoms and preserved heart function, though AF can recur and require ongoing management. Regular follow-up and treatment adjustment are essential, as the clinical picture can evolve with aging and the emergence of new comorbidities. stroke heart failure ischemic stroke