A 58-year-old woman with a history of paroxysmal atrial fibrillation (PAF) and a CHA₂DS₂-VASc score of 3 presents with a new episode of AF lasting 8 hours. She is haemodynamically stable, denies chest pain, and troponin is negative. She is not on any anticoagulant. What is the most appropriate next step in management?

Explanation

## Clinical Scenario Analysis This patient has **paroxysmal AF with a CHA₂DS₂-VASc score of 3** (high stroke risk), presenting with **symptomatic AF of 8 hours duration**. She is haemodynamically stable and troponin-negative. ## Stroke Risk Stratification in AF **Key Point:** CHA₂DS₂-VASc ≥1 in males and ≥2 in females mandates **anticoagulation**, regardless of AF type (paroxysmal, persistent, permanent). ### CHA₂DS₂-VASc Score Components | Component | Points | |-----------|--------| | **C** — Congestive heart failure | 1 | | **H** — Hypertension | 1 | | **A₂** — Age ≥75 years | 2 | | **D** — Diabetes mellitus | 1 | | **S₂** — Prior stroke/TIA/thromboembolism | 2 | | **V** — Vascular disease (MI, PAD, aortic plaque) | 1 | | **A** — Age 65–74 years | 1 | | **Sc** — Sex category (female) | 1 | **Score ≥2 in females (or ≥1 in males) → Anticoagulation recommended** ## Management Algorithm for Stable AF ≤48 Hours ```mermaid flowchart TD A[AF duration ≤48 hours, stable]:::outcome --> B{CHA₂DS₂-VASc score?}:::decision B -->|≥2 female or ≥1 male| C[Initiate anticoagulation]:::action B -->|0 female or 0 male| D[No anticoagulation needed]:::action C --> E{Rhythm control desired?}:::decision E -->|Yes| F[Rate control + DOAC/warfarin, then consider cardioversion]:::action E -->|No| G[Rate control + anticoagulation, monitor]:::action D --> H[Rate control only]:::action ``` ## Why Anticoagulation BEFORE Cardioversion? **High-Yield:** In AF lasting >48 hours (or unknown duration), **anticoagulation must precede cardioversion** to prevent thromboembolic stroke. Options: 1. **Immediate anticoagulation + early cardioversion** (if duration ≤48 hours AND TEE rules out LA thrombus) 2. **Anticoagulation for 3 weeks, then cardioversion** (if duration >48 hours or unknown) 3. **Transesophageal echocardiography (TEE)** to exclude LA/LAA thrombus, allowing safe cardioversion within 24 hours even if duration >48 hours **Clinical Pearl:** This patient's AF duration is 8 hours (≤48 hours), so she is a candidate for **early cardioversion with anticoagulation**. However, the safest approach is to **start anticoagulation immediately** and then decide on rhythm control strategy. ## Why This Option Is Correct - **CHA₂DS₂-VASc = 3** → Anticoagulation mandatory - **AF ≤48 hours** → Can proceed with rate control + anticoagulation; cardioversion can be considered later if rhythm control desired - **DOAC preferred** over warfarin in most cases (faster onset, no INR monitoring, better compliance) - **Rate control** (IV CCB or beta-blocker) should accompany anticoagulation **Mnemonic:** **SAFE AF** = **S**troke risk (CHA₂DS₂-VASc), **A**nticoagulation first, **F**ocus on rate control, **E**arly cardioversion if ≤48 hrs + anticoagulated.