What are the first-line treatments for Atrial Fibrillation (AF) with Wolff-Parkinson-White (WPW) syndrome, AF post-cardiac surgery, AF in Heart Failure (HF) with reduced Ejection Fraction (EF), and AF in thyrotoxicosis?

First-Line Treatments for Atrial Fibrillation in Specific Clinical Scenarios

AF with WPW Syndrome

For patients with AF and WPW syndrome with rapid ventricular response, prompt direct-current cardioversion is recommended if the patient is hemodynamically compromised. 1

• For hemodynamically stable patients with pre-excited AF and rapid ventricular response, intravenous procainamide or ibutilide is recommended to restore sinus rhythm or slow the ventricular rate 1
• Catheter ablation of the accessory pathway is recommended in symptomatic patients with pre-excited AF, especially if the accessory pathway has a short refractory period allowing rapid antegrade conduction 1
• Administration of intravenous amiodarone, adenosine, digoxin, or nondihydropyridine calcium channel antagonists is potentially harmful as these drugs can accelerate the ventricular rate and should be avoided 1
• Despite some historical use of amiodarone in WPW-AF, evidence suggests it may be dangerous and is not superior to procainamide 2

AF Post-Cardiac Surgery

Beta blockers are the first-line treatment for AF following cardiac surgery unless contraindicated. 1

• Nondihydropyridine calcium channel blockers are recommended when beta blockers are inadequate to achieve rate control 1
• For rhythm control, it is reasonable to restore sinus rhythm pharmacologically with ibutilide or direct-current cardioversion 1
• Amiodarone is reasonable as prophylactic therapy for patients at high risk of postoperative AF 1
• For patients with postoperative AF that does not spontaneously revert to sinus rhythm, it is reasonable to manage with rate control and anticoagulation with cardioversion during follow-up 1
• Rate control should target a heart rate <100 bpm when deemed safe from surgical bleeding 1

AF in HF with Reduced EF

For patients with AF and HFrEF, intravenous digoxin or amiodarone is recommended as first-line therapy for acute rate control. 3

• Beta blockers should be used cautiously in patients with decompensated heart failure 3
• For long-term management, a combination of digoxin and a beta blocker is reasonable to control both resting and exercise heart rate 3
• For patients with persistent symptoms despite rate control, a rhythm control strategy may be reasonable 3
• Oral amiodarone may be considered when resting and exercise heart rate cannot be adequately controlled using other agents 3
• AV node ablation with ventricular pacing is reasonable when pharmacological therapy is insufficient or not tolerated 3
• Nondihydropyridine calcium channel antagonists, dronedarone, and high-dose beta blockers should not be given to patients with decompensated HF 1

AF in Thyrotoxicosis

Beta blockers are recommended to control ventricular rate in patients with AF complicating thyrotoxicosis unless contraindicated. 1

• When beta blockers cannot be used, nondihydropyridine calcium channel antagonists are recommended for rate control 1
• Treatment is directed primarily toward restoring a euthyroid state, which is usually associated with spontaneous reversion of AF to sinus rhythm 1
• Antiarrhythmic drugs and cardioversion often fail to achieve sustained sinus rhythm while thyrotoxicosis persists; therefore, efforts to restore normal sinus rhythm may be deferred until the patient is euthyroid 1
• Anticoagulation should be guided by CHA₂DS₂-VASc risk factors, as evidence suggests embolic risk is not necessarily increased independent of other stroke risk factors 1
• If thyrotoxicosis is due to long-term amiodarone use, the drug should be discontinued 1

Important Considerations

• For all scenarios, assessment of stroke risk and appropriate anticoagulation is essential 1, 3
• In AF with WPW, avoid drugs that block only the AV node (calcium channel blockers, beta blockers, digoxin) as they can paradoxically increase conduction through the accessory pathway 1, 4
• For post-cardiac surgery AF, prophylactic strategies including beta blockers, amiodarone, or posterior left pericardiotomy may reduce incidence 1
• In HFrEF patients, lenient rate control (resting heart rate <110 bpm) may be an acceptable initial approach unless symptoms call for stricter control 3
• For thyrotoxicosis, treatment of the underlying condition is paramount before focusing on rhythm control strategies 1