Long-term rhythm control for atrial fibrillation
Catheter ablation or antiarrhythmic drugs can be used for long-term rhythm control for atrial fibrillation. The aim of treatment is to reduce the patient’s symptoms.
The long-term efficacy of antiarrhythmic drugs is modest. Catheter ablation is equivalent to pharmacological therapy in terms of hard outcome measures (eg mortality, thromboembolism, bleeding); however, catheter ablation has better quality of life outcomesHindricks, 2021Mark, 2019.
If catheter ablation is the preferred rhythm control option, consider early referral to a cardiologist as the outcomes of catheter ablation are better if the procedure is performed in the early stages of atrial fibrillation (less than 12 months from diagnosis)NHFA CSANZ Atrial fibrillation guideline working group, 2018.
Catheter ablation is less likely to succeed in patients with longstanding persistent atrial fibrillation, marked left atrial dilatation, and in those with untreated risk factors for atrial fibrillation (eg obesity)NHFA CSANZ Atrial fibrillation guideline working group, 2018.
The decision to use long-term pharmacological rhythm control should be balanced with the potential adverse effects of the antiarrhythmic drug, and the patient’s comorbidities, symptoms and preference. Patients who do not respond to one antiarrhythmic drug may respond to an alternative antiarrhythmic drug.
Sotalol can be considered to maintain sinus rhythm in patients with atrial fibrillation who have coronary artery disease and normal left ventricular function. A suitable regimen is:
sotalol 40 mg orally, twice daily, increasing if required up to 160 mg twice dailyHindricks, 2021Piccini, 2016. sotalol sotalol sotalol
Avoid sotalol in patients with a left ventricular ejection fraction of 40% or less, or in patients with severe kidney impairment. Monitor patients taking sotalol for QT prolongation via electrocardiogram (ECG); stop the drug if QT or QTc interval exceeds 0.5 seconds or increases by more than 20% from baseline. Sotalol has a greater incidence of QT prolongation in elderly patients, particularly those with kidney impairmentHindricks, 2021Waldo, 1996.
Flecainide can be considered to maintain sinus rhythm for patients with atrial fibrillation who have a left ventricular ejection fraction known to be greater than 40% and no significant coronary artery disease. In patients with underlying structural heart disease and atrial fibrillation, the use of flecainide has been associated with life-threatening and occasionally fatal ventricular arrhythmias; other antiarrhythmic drugs should be trialled before flecainide is used in these patients. If considered appropriate, a suitable flecainide regimen is:
flecainide 50 mg orally, twice daily, increasing if required up to 150 mg twice dailyPiccini, 2016. flecainide flecainide flecainide
Flecainide has a half-life of 12 to 27 hours; dose increases should be made no more frequently than once every 4 days. For patients with atrial fibrillation, flecainide is most often used in combination with an AV nodal blocking drug (eg a beta blocker, diltiazem, verapamil). This combination decreases the risk of conversion to atrial flutter with 1:1 conduction.
Amiodarone can be considered for long term use if flecainide or sotalol are not suitable to maintain sinus rhythm in patients with atrial fibrillation. A suitable regimen is:
amiodarone 200 mg orally, 3 times daily for 1 week, then twice daily for 1 week, then once dailyHindricks, 2021. amiodarone amiodarone amiodarone
The loading and maintenance doses of amiodarone must be adjusted according to patient response, tolerability and body weight, because of wide interpatient variability in absorption. Amiodarone has the potential to cause serious lung, thyroid and liver adverse effects if it is used for extended periods. The patient’s general practitioner should monitor liver biochemistry and thyroid function if amiodarone is used long term.
For patients with longstanding persistent atrial fibrillation who do not respond to antiarrhythmic drug therapy, seek specialist cardiology advice regarding catheter ablation.