cardioversion in atrial fibrillation

Last edited 05/2021 and last reviewed 05/2021

Around 50% of the patients with new onset atrial fibrillation convert back to sinus rhythm within the first 24 hours (1).

Cardioversion is a therapeutic intervention which returns the heart's rhythm to sinus rhythm in patients who do not convert spontaneously (1).

  • it avoids the complications of atrial fibrillation, namely:
    • thromboembolism
    • heart failure
    • death

Cardioversion may be performed in two ways:

  • electrical cardioversion (ECV)
  • pharmacological cardioversion (PCV) (2)

When to offer rate or rhythm control (2)

  • offer rate control as the first-line strategy to people with atrial fibrillation, except in people:
    • whose atrial fibrillation has a reversible cause
    • who have heart failure thought to be primarily caused by atrial fibrillation
    • with new-onset atrial fibrillation
    • with atrial flutter whose condition is considered suitable for an ablation strategy
    • to restore sinus rhythm for whom a rhythm control strategy
    • would be more suitable based on clinical judgement

Cardioversion (2)

  • carry out emergency electrical cardioversion, without delaying to achieve anticoagulation, in people with life-threatening haemodynamic instability caused by new-onset atrial fibrillation

  • for people having cardioversion for atrial fibrillation that has persisted for longer than 48 hours, offer electrical (rather than pharmacological) cardioversion

  • consider amiodarone therapy starting 4 weeks before and continuing for up to 12 months after electrical cardioversion to maintain sinus rhythm, and discuss the benefits and risks of amiodarone with the person

  • for people with atrial fibrillation of greater than 48 hours' duration, in whom elective cardioversion is indicated
    • both transoesophageal echocardiography (TOE)-guided cardioversion and conventional cardioversion should be considered equally effective
    • a TOE-guided cardioversion strategy should be considered:
      • where experienced staff and appropriate facilities are available and
      • where a minimal period of precardioversion anticoagulation is indicated due to the person's choice or bleeding risk

In patients with AF without haemodynamic instability for whom cardioversion is indicated:

  • the advantages and disadvantages of both pharmacological and electrical cardioversion should be discussed with patients before initiating treatment
  • where AF onset was within 48 hours previously, either pharmacological or electrical cardioversion should be performed
  • for those with more prolonged AF (onset more than 48 hours previously) electrical cardioversion should be the preferred initial treatment option (2)

In people with atrial fibrillation in whom the duration of the arrhythmia is greater than 48 hours or uncertain and considered for long-term rhythm control, delay cardioversion until they have been maintained on therapeutic anticoagulation for a minimum of 3 weeks

  • during this period offer rate control as appropriate