E.g. infection, myocardial ischaemia, metabolic derangement, LVF etc. This may be all that is required. If resting rate is >100 bpm, or there is evidence of myocardial ischaemia or LVF precipitated by the rapid heart rate, rate control is indicated.

• First line therapy should be β –blockade Bisoprolol 2.5mg od or Metoprolol 25mg bd - up titrate as necessary. (Metoprolol has a shorter half life and should be used in patients where there is concern about tolerability of β –blockers.)
• Where β –blockers are contra-indicated, rate limiting Ca2+ channel blockers such as Diltiazem or Verapamil can be used (caution in heart failure)
• Digoxin- Use for inactive, elderly or evidence of LVF or hypotension.
  Dose: - 500μg at baseline and a further 500μg dose 6 hours later, followed by 250μg daily. (Reduced with abnormal renal function.) Use oral Digoxin unless unable to swallow.

Only in patients who are acutely unwell due to high ventricular rates and hypotension. e.g. patients in cardiogenic shock. Always weigh, the risks of anaesthetic and embolic complication.

Early cardioversion
Restoration of sinus rhythm is sometimes necessary or desirable e.g. in patients with paroxysmal AF and in the post operative period.
If the patient is not adequately anti-coagulated, cardioversion should not be undertaken if the duration of AF is >48hrs. Patient can be considered for out-patient cardioversion following at least 3 weeks of anti-coagulation.
If patients are at medium or high risk of embolic complications, anti-coagulation in the longer term should be considered and instituted following cardioversion. If there is doubt about the duration of AF, or early cardioversion is important clinically, TOE guided cardioversion can be considered.

Chemical cardioversion
This can be done with either Amiodarone or Flecainide. Flecainide should not be used in patients with ischaemic heart disease or a structurally abnormal heart. D/W cardiologist.