Atrial Fibrillation
An irregular, often rapid heart rhythm that increases stroke risk.
Overview
Atrial fibrillation (AF) is the most common sustained arrhythmia. The atria quiver instead of contracting effectively, leading to palpitations, breathlessness and a substantially raised risk of stroke. Treatment focuses on rate or rhythm control and anticoagulation based on stroke-risk scores (CHA₂DS₂-VASc).
Symptoms
- • Palpitations or irregular pulse
- • Breathlessness
- • Fatigue
- • Dizziness
- • Chest discomfort
- • Often asymptomatic
Risk factors
- • Age >65
- • Hypertension
- • Heart failure
- • Valve disease
- • Hyperthyroidism
- • Excess alcohol
- • Sleep apnoea
- • Obesity
Causes
- • Structural heart disease
- • Hyperthyroidism
- • Acute illness or sepsis
- • Alcohol binge ('holiday heart')
- • Idiopathic
🚨 Red flags — seek urgent care
- • Chest pain with palpitations
- • Syncope or near-fainting
- • Severe breathlessness
- • Signs of stroke (FAST)
When to seek care
- • New irregular pulse
- • Symptoms affecting daily activity
- • Bleeding while on anticoagulation
Diagnosis
- • 12-lead ECG showing irregularly irregular rhythm with absent P waves
- • Ambulatory ECG (24-h, 48-h, or implantable loop recorder) for paroxysmal AF
- • Bloods: TFTs, U&E, FBC; echocardiogram to assess structural heart disease
Treatment
- • Stroke prevention with CHA2DS2-VASc ≥1 (men) / ≥2 (women): DOAC first-line (apixaban, rivaroxaban, edoxaban, dabigatran)
- • Rate control: beta-blocker or rate-limiting CCB; digoxin in sedentary patients
- • Rhythm control: flecainide / propafenone (no structural heart disease), amiodarone, sotalol; catheter ablation
- • Cardioversion (electrical or pharmacological) for new-onset AF with appropriate anticoagulation
- • Treat reversible drivers (alcohol, sleep apnoea, hyperthyroidism, hypertension)
Prevention
- • Control blood pressure, weight and alcohol intake
- • Treat obstructive sleep apnoea
- • Manage thyroid disease
- • Regular aerobic exercise of moderate intensity
Complications
- • Ischaemic stroke and systemic embolism
- • Heart failure (tachycardia-induced cardiomyopathy)
- • Reduced exercise tolerance and quality of life
- • Bleeding from anticoagulation
- • Cognitive decline
Education & self-care
This guidance is reviewed by Dr. Handel Emery, MD, FRCP (UK) and last updated 2026-06-08. It is educational and not a substitute for professional medical advice.
Frequently asked questions
Do I need a blood thinner?
Most people with AF benefit from anticoagulation based on their CHA₂DS₂-VASc score. Your clinician will weigh stroke vs bleeding risk.
Can AF be cured?
Catheter ablation can restore normal rhythm in selected patients, especially when AF is paroxysmal and symptomatic.
Do I have to take a blood thinner forever?
If your CHA₂DS₂-VASc stroke risk score is 2 or more (men) or 3 or more (women), lifelong anticoagulation is recommended even if your rhythm later returns to normal — the underlying stroke risk persists.
Is cardioversion a cure?
Cardioversion restores normal rhythm in most people initially, but AF returns within a year in up to half. Ablation provides longer-term rhythm control for selected patients.
Can lifestyle changes reverse AF?
Weight loss, alcohol reduction, treating sleep apnoea and good blood pressure control significantly reduce AF burden and recurrence. Aggressive risk-factor modification is now considered a cornerstone of treatment.