Atrial FibrillationEmergency

Cardiology · Ward Pathways · Free — no sign-in

Irregularly irregular pulse, no P waves, rapid rate

Calculators:
  1. Unstable (chest pain, CHF, ↓SBP, confusion) → Immediate synchronized cardioversion (AF/AFL: begin at 200 J biphasic)
  2. Stable → rate control (or early rhythm control): β-blocker (metoprolol) OR CCB (diltiazem/verapamil) OR digoxin. Early rhythm control (within 12 months of diagnosis) reduces cardiovascular outcomes in selected patients (EAST-AFNET 4, Class 2a); catheter ablation is Class 1 first-line rhythm control in selected patients (younger, few comorbidities, HFrEF)
  3. Anticoagulate by CHA₂DS₂-VASc: men ≥1 / women ≥2 → consider; men ≥2 / women ≥3 → DOAC (apixaban/rivaroxaban/dabigatran) preferred over warfarin. Aspirin NOT recommended for stroke prevention
Decision tree
Haemodynamically unstable (chest pain, CHF, ↓BP, ↓GCS)?
Yes
Immediate synchronised cardioversion
No
Onset <48 h or anticoagulated/TEE clear?
Yes
Rate control; cardiovert if chosen; start anticoagulation by CHA₂DS₂-VASc
No
Rate control + anticoagulate ≥3 wk before elective cardioversion (or TEE-guided)

Order set

  • ECG
  • U&E, Mg, TFT
  • Troponin if ischaemic
  • Echo
  • Rate control + anticoagulation decision

Criteria

AdmitInstability, ischaemia, or heart failure from AF
ICURefractory instability needing cardioversion/support
DischargeRate controlled, anticoagulation decided (CHA₂DS₂-VASc), reversible causes addressed

Never

  • Anticoagulate for AF <48 h before cardioversion without TEE
  • Chemically convert before controlling rate

Key

  • Early rhythm control (≤12 months of diagnosis) reduces cardiovascular outcomes in selected patients (EAST-AFNET 4); rate control remains appropriate for many.
  • Catheter ablation is Class 1 first-line rhythm control in selected patients; LAA occlusion (Class 2a) if long-term anticoagulation contraindicated.
  • Pre-excited AF (WPW + AF) → procainamide or ibutilide; avoid AV-nodal blockers (see case 7).
Clinical detail — differentials, red flags, pitfalls, disposition
Red flags
  • Hypotension/chest pain/CHF → cardiovert
  • Pre-excited AF
Differentials
  • Atrial flutter
  • MAT
  • Frequent ectopy
Common mistakes
  • Aspirin for stroke prevention
  • AV-nodal blockers in WPW
  • Cardioverting >48 h without anticoagulation/TEE
Disposition & follow-up

Rate control, CHA₂DS₂-VASc-based anticoagulation, outpatient rhythm review.

Discharge package
MedicationsRate control; anticoagulation per CHA₂DS₂-VASc
Follow-upReview rhythm/rate; anticoagulation monitoring
LifestyleAlcohol moderation, treat OSA, BP control
Warning symptomsPalpitations with chest pain/syncope, bleeding on anticoagulant
💊 Treatment detail — doses & preparation
Metoprololβ-blocker
DoseIV 2.5–5 mg q5 min ×3; PO 25–100 mg BD (succinate OD for HF)
PreparationIV 1 mg/mL ampoule undiluted, slow push; PO immediate- vs extended-release not interchangeable mg-for-schedule
MonitorHR, BP; avoid in decompensated HF/asthma/high-grade block
Diltiazemnon-DHP CCB
DoseIV 0.25 mg/kg over 2 min, then 5–15 mg/h; PO 60–120 mg TDS (MR OD available)
PreparationIV 25 mg in 5 mL undiluted or in 100 mL NS; infusion 125 mg in 500 mL NS
MonitorHR, BP, AV block; avoid in HFrEF/WPW
Digoxincardiac glycoside
DoseLoad 500 mcg PO/IV ×2, 6 h apart, then 62.5–250 mcg OD (lower in elderly/CKD)
PreparationPO tablets/elixir; IV 250 mcg/mL dilute in 50 mL NS over ≥10 min
MonitorLevel 6 h post-dose (target 0.5–0.9), K⁺, Mg²⁺, renal function, toxicity signs
ApixabanDOAC (anti-Xa)
Dose5 mg BD (2.5 mg BD if ≥2 of: age ≥80, weight ≤60 kg, Cr ≥133). PE/DVT: 10 mg BD ×7 d then 5 mg BD
Preparation2.5/5 mg tablets (crushable)
MonitorBleeding, renal function; no routine monitoring
Amiodarone IVantiarrhythmic
DoseArrest: 300 mg IV/IO bolus (then 150 mg). Stable: 150 mg over 10 min, then 1 mg/min ×6 h, 0.5 mg/min ×18 h
PreparationBolus 300 mg in 20–50 mL D5W; infusion 900 mg in 500 mL D5W (glass/non-PVC)
MonitorQT, LFTs, thyroid; long half-life — interacts with warfarin/digoxin
📖 ESC / ACC-AHA-HRS Atrial FibrillationReviewed July 2026

← Mitral Stenosis  ·  SVT / VT / WPW →

More Cardiology pathways

Part of Cardiology in Ward Pathways — open the interactive version.

ICU Decoded — original critical-care and internal-medicine pathways by Dr Javed Akhtar, each cited to a current guideline. For education and quick reference; verify every dose against local protocols before prescribing.

Open the app · Ward Pathways — 113 free cases · ICU Decoded chapters · Aladin Chirag bedside tools

About · Medical disclaimer · Privacy · Contact