- Drugs for rhythm and rate control

If the aim is to control a patient’s heart rate, the usual drug of choice is a ß-blocker.

• Diltiazem may be used in patients in whom beta blockade is contraindicated or not tolerated
• Digoxin may be used in patients with heart failure
• Amiodarone may be used to assist with rate control but is most useful in maintaining rhythm control

When possible you should always seek expert help in selecting the best choice of treatment for rate control in each individual patient.

If the duration of atrial fibrillation is under 48 hours, and rhythm control is considered the appropriate strategy, chemical cardioversion may be appropriate.

• Drugs such as flecainide may be used but you should always seek expert help before prescribing it to a patient. Do not use flecainide in the presence of heart failure, known left ventricular impairment or ischaemic heart disease, or a prolonged QT interval
• Amiodarone (300 mg intravenously over 20 – 60 min followed by 900 mg over 24 h) may be used to attempt chemical cardioversion but is often less effective than drugs like flecainide and can take longer
• Electrical cardioversion remains an option in this setting and will restore sinus rhythm in more patients than chemical cardioversion