Summary

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, characterised by chaotic, irregular atrial electrical activity resulting in an irregularly irregular ventricular response. AF affects 2-4% of adults, rising to 10-17% in those over 80. The condition is associated with a 5-fold increased risk of stroke and a 2-fold increased risk of mortality. Modern management follows the ABC pathway: Anticoagulation (stroke prevention), Better symptom control (rate or rhythm control), and Cardiovascular/Comorbidity management. DOACs are now preferred over warfarin for most patients. Early rhythm control (EAST-AFNET 4 trial) and catheter ablation (pulmonary vein isolation) have become central to contemporary management.

Key Facts

• Definition: Supraventricular arrhythmia with disorganised atrial activation, absent P waves, and irregular R-R intervals
• Prevalence: 2-4% adults; 10-17% over 80 years
• Stroke Risk: 5x increased (major source of morbidity)
• Anticoagulation: CHA₂DS₂-VASc ≥2 (male) or ≥3 (female) = anticoagulation indicated
• Rate vs Rhythm: Both strategies acceptable; early rhythm control increasingly favoured
• Ablation: PVI first-line for paroxysmal AF in selected patients

Clinical Pearls

"AF Begets AF": Electrical remodelling from AF promotes AF persistence. Early rhythm control may prevent progression.

"Stroke Prevention First": Anticoagulation is the most important intervention for reducing mortality — regardless of rate vs rhythm strategy.

"CHA₂DS₂-VASc Drives Anticoagulation": Use the score systematically. DOACs are preferred over warfarin for non-valvular AF.

Why This Matters Clinically

AF is common, often undertreated, and causes significant morbidity (stroke, heart failure) and mortality. Optimal management including anticoagulation saves lives.

Structured Approach

Pulse:

• Irregularly irregular
• Rate

JVP:

• Absent a-waves

Precordium:

• Apex beat (displaced in heart failure)
• Variable S1
• Murmurs (valvular disease)

Signs of Heart Failure:

• Elevated JVP, oedema, crackles

Signs of Underlying Cause:

• Thyroid examination
• Signs of hypertension, valvular disease

Natural History

• Progressive condition (paroxysmal → persistent → permanent)
• AF begets AF (electrical remodelling)
• Early rhythm control may prevent progression

Mortality

Key Guidelines

1. ESC Guidelines for the Diagnosis and Management of AF (2020) — Gold standard.

2. NICE NG196: Atrial fibrillation (2021)

Landmark Trials

EAST-AFNET 4 (2020) — Early rhythm control

• Key finding: Early rhythm control reduced cardiovascular outcomes in AF
• Clinical Impact: Supports rhythm control early in disease course

CASTLE-AF (2018) — Ablation in HF

• Key finding: Catheter ablation reduced mortality and HF hospitalisation in HFrEF
• Clinical Impact: Ablation increasingly first-line in AF with HF

Evidence Strength

What is Atrial Fibrillation?

Atrial fibrillation (AF) is an irregular heartbeat where the top chambers of your heart (atria) beat chaotically instead of regularly. This makes your pulse fast and irregular.

Why does it matter?

The main concern is stroke. When blood doesn't flow smoothly, clots can form in your heart and travel to your brain. AF also makes your heart less efficient and can cause tiredness.

How is it treated?

1. Blood thinners: The most important treatment to prevent stroke
2. Heart rate control: Medications to slow your heart
3. Rhythm control: Trying to restore normal rhythm (medications, electrical shock, or ablation)
4. Lifestyle: Weight loss, reducing alcohol, treating sleep apnoea, exercise

What to expect

• AF is usually a lifelong condition
• With good treatment, you can live a normal life
• Regular check-ups and blood tests may be needed
• Ablation can cure AF in some people

When to seek urgent help

Call 999 or go to A&E if:

• You have chest pain
• You feel very faint or collapse
• You have sudden weakness or difficulty speaking (signs of stroke)
• You are very short of breath