Atrial Fibrillation (AFib) is the most common sustained cardiac arrhythmia and is characterized by disorganized, rapid electrical activity in the atria, leading to an irregular and often rapid heart rhythm. Instead of contracting effectively, the atria fibrillate, resulting in impaired atrial emptying, loss of atrial contribution to ventricular filling, and an increased risk of thrombus formation. AFib is a major cause of stroke, heart failure, and cardiovascular morbidity worldwide.

AFib is broadly classified into paroxysmal AFib (self-terminating episodes lasting less than 7 days), persistent AFib (lasting more than 7 days or requiring intervention for termination), long-standing persistent AFib (continuous AFib for more than 12 months), and permanent AFib, where rhythm control is no longer pursued. The progression of AFib reflects underlying structural and electrical remodeling of the atria.

The pathophysiology of AFib involves atrial dilation, fibrosis, inflammation, and electrical heterogeneity, which create a substrate for multiple re-entrant electrical circuits. Common precipitating and associated conditions include hypertension, coronary artery disease, heart failure, valvular heart disease (especially mitral valve disease), cardiomyopathy, diabetes, obesity, sleep apnea, hyperthyroidism, and excessive alcohol intake. Advancing age is one of the strongest risk factors.

Clinical presentation varies widely. Some patients experience prominent symptoms such as palpitations, irregular heartbeat, shortness of breath, fatigue, dizziness, chest discomfort, or reduced exercise tolerance. Others may remain asymptomatic, with AFib detected incidentally during routine examination or ECG. Importantly, asymptomatic AFib still carries a significant risk of stroke and systemic embolism.

Diagnosis is established through electrocardiography (ECG), which demonstrates an irregularly irregular rhythm with absence of distinct P waves. Extended rhythm monitoring using Holter monitors or event recorders may be required in intermittent cases. Echocardiography is essential to assess atrial size, ventricular function, valvular disease, and to guide management decisions. Additional investigations may include thyroid function tests, electrolyte assessment, and cardiac imaging.

Management of AFib focuses on three core objectives: stroke prevention, rate or rhythm control, and management of underlying conditions. Stroke prevention is achieved through anticoagulation therapy based on validated risk stratification tools such as the CHA?DS?-VASc score. Oral anticoagulants significantly reduce the risk of ischemic stroke and are central to AFib management.

Rate control strategies aim to regulate ventricular response using medications such as beta-blockers or calcium channel blockers. Rhythm control, pursued in selected patients, may involve antiarrhythmic drugs, electrical cardioversion, or catheter-based ablation procedures targeting pulmonary vein triggers. In patients with recurrent or drug-refractory AFib, catheter ablation has become an increasingly effective treatment option.

Early diagnosis, comprehensive risk assessment, and individualized treatment significantly reduce complications, improve symptom control, and enhance quality of life in patients with atrial fibrillation.