Medical guidelines and references.

Atrial FibrillationCardiology

Atrial Fibrillation diagnosis & Management

Updated: 1st May 2024


  • Palpate carotid for more reliable measure of pulse.
  • Suspect paroxysmal AF if symptoms are episodic and last less than 48 hours
  • Absence of irregular pulse makes AF unlikely. Its presence does not reliably indicate AF.
  • ECG in AF has – no P-wave, a chaotic baseline and an irregular ventricular rate
  • Rate is usually 160-180 BPM, but can be lower in typically in asymptomatic patients
  • If paroxysmal AF suspected and not found on ECG
    • Arrange ambulatory ECG
    • 24 hour ECG if symptoms < 24h apart, or event recorder ECG/7 Day Holter if > 24h apart


  • Onset in last 48h
    • If haemodynamic instability (Pulse > 150BPM) and/or Low BP (systolic < 90) or LOC, severe dizziness, chest pains or SOB -> A&E for electrical cardioversion
    • Else – consider management in primary care if appropriate or refer to acute medical unit for immediate cardioversion
      • if has suspected decompensated HF, seek specialist advice on use of BB and avoid CCB.
      • Most people with symptomatic acute onset AF are initially managed in secondary care.
  • For others (including paroxysmal AF)
    • Admit if – haemodynamic instability, or other serious associated condition, e.g. CVA, PE, pneumonia, thyrotoxicosis, severe HF
    • Else – Screen for causes of AF and manage or refer as appropriate
      • Cardiac – HTN, Valve disease, HF, IHD
      • Respiratory – LRTI, Lung cancer
      • Systemic causes – Alcohol, hyperthyroidism, Electrolyte imbalance (U&E, calcium and magnesium), infection, DM
    • Cardiology referral needed if
      • A pre-excitation syndrome e.g. WPW syndrome
      • Valve disease associated with AF
      • HF suspected
      • For consideration of pharmacological or electrical rhythm control (Cardioversion)
        • AF has reversible cause – e.g. LRTI
        • HF caused or worsened by AF
    • Primary care management
      • Assess stroke risk using CHA2DS2VASc assessment tool
      • Assess bleeding risk using ORBIT bleeding risk tool 
      • If anticoagulation necessary
        • Offer DOAC
          • Apixaban, Rivaroxaban, Dabigatran and Edoxaban are all suitable
            • Apixaban and Rivaroxaban are reversed by Andexanet alfa and Dabigatran is reversed by Idarucizumab. Edoxaban has no reversing agent.
            • Do not withhold solely because of age or falls risk
        • Warfarin if DOAC not suitable
        • If anticoagulation is contraindicated – consider combination Aspirin and Clopidogrel
      • Rate control
        • 1st line – BB (other than sotalol) or CCB (Diltiazem or verapamil note avoid in HF with reduced EF)
        • 2nd line – Digoxin (for non-paroxysmal AF if they do little/no exercise or others rate limiting drugs ruled out)
        • Arrange follow up in 1 week
          • Aim 60-80 BMP at rest, and 90-115 at moderate exercise
            • Titrate up to maximum dosage if needed to control HR and/or BP
            • If still poorly controlled – consider combination with any two of BB, digoxin or Diltazem*
              • * Specialist advice needed for BB and Diltazem combination (risk bradycardia, AV block, asystole or sudden death)
          • Consider referral for cardioversion if symptoms continue or rate control fails – to see specialist within 4 weeks