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Atrial Fibrillation

Cardiovascular Palpitations Dizziness/syncope Stroke

Atrial Fibrillation (AF) is a common supraventricular arrhythmia characterized by rapid, irregular atrial activation and an irregular ventricular response. Management involves stroke prevention, rate control, and rhythm control.

🎯 Key Learning Objectives

  1. Identify AF on ECG (absent P waves, irregularly irregular rhythm).
  2. Calculate stroke risk using CHA2DS2-VASc score.
  3. Assess bleeding risk using ORBIT or HAS-BLED scores.
  4. Implement rate control strategies (Beta-blockers, Diltiazem).
  5. Determine the need for rhythm control (cardioversion) versus rate control.
  6. Recognize valvular AF as an absolute indication for Warfarin over DOACs.

🔬 Pathophysiology

Multiple re-entrant circuits within the atria, often triggered by pulmonary vein ectopics, lead to disorganized electrical activity. Loss of atrial contraction causes stasis in the left atrial appendage, increasing thrombus risk.

🩺 Clinical Features

Symptoms
  • Palpitations
  • Shortness of breath
  • Chest pain
  • Lightheadedness
  • Syncope
Signs
  • Irregularly irregular pulse
  • Variable intensity of first heart sound
  • Pulse deficit (radial vs apical pulse disparity)

🔬 Investigations

🛏️ Bedside
  • ECG
  • Manual pulse check
🩸 Bloods
  • TFTs (common trigger)
  • U&Es
  • Clotting profile
  • Full Blood Count
📷 Imaging
  • Echocardiogram (to check for structural/valvular heart disease)
⚗️ Special
  • 24-hour Holter monitoring
  • Transoesophageal echo (prior to cardioversion)

💊 Management

🚨 Acute Management
  • Heparin if high risk
  • DC Cardioversion if haemodynamically unstable
  • Flecainide or Amiodarone for pharmacological cardioversion
📋 Long-Term
  • Anticoagulation (Apixaban, Rivaroxaban, or Warfarin)
  • Beta-blocker (first-line rate control)
  • Digoxin (sedentary patients)
🏃 Lifestyle
  • Alcohol reduction
  • Caffeine moderation
  • Weight loss
  • CPAP for sleep apnoea

⚠️ Complications

Ischaemic stroke Tachycardia-induced cardiomyopathy Heart failure Thromboembolism

⭐ High-Yield Pearls

  • A CHA2DS2-VASc score of 2+ in males (1+ in females) requires anticoagulation.
  • Rate control is first-line for most except those with reversible cause, new-onset (<48h), or heart failure.
  • DOACs are preferred over Warfarin unless the patient has a metallic valve or mitral stenosis.
  • Always check TFTs in new-onset AF.
  • If AF duration >48h, anticoagulation is required for 3 weeks prior to elective cardioversion.
📖 GUIDELINES: NICE NG196 ESC AF Guidelines

❓ Practice Questions

Q1. A 62-year-old man presents to the emergency department with 40 minutes of crushing retrosternal chest pain radiating to his left jaw. His ECG shows 3mm ST-segme…
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Q2. A 74-year-old woman with a history of hypertension presents with increasing breathlessness on exertion and ankle swelling. Echocardiogram reveals a left ventric…
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Q3. An 82-year-old man is found to have an irregularly irregular pulse during a routine health check for his Type 2 Diabetes. An ECG confirms atrial fibrillation wi…
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