From the Guidelines
Management of atrial fibrillation in patients with Wolff-Parkinson-White syndrome requires immediate attention to prevent ventricular fibrillation and sudden cardiac death, with catheter ablation of the accessory pathway being the definitive treatment. The most recent and highest quality study 1 recommends prompt direct-current cardioversion for patients with AF, Wolff-Parkinson-White syndrome, and rapid ventricular response who are hemodynamically compromised. For stable patients, intravenous procainamide or ibutilide can be used to restore sinus rhythm or slow the ventricular rate 1. Key considerations in managing AF with WPW include:
- Avoiding AV nodal blocking agents like beta-blockers, calcium channel blockers, digoxin, and adenosine, as they can increase conduction through the accessory pathway and potentially precipitate ventricular fibrillation
- Using procainamide or ibutilide, which block conduction in both the AV node and accessory pathway, to restore sinus rhythm in stable patients
- Considering catheter ablation of the accessory pathway in symptomatic patients, particularly those with syncope due to rapid heart rate or those with a short bypass tract refractory period 1 The goal of treatment is to prevent morbidity and mortality associated with rapid ventricular response and ventricular fibrillation, while also improving quality of life for patients with AF and WPW syndrome.
From the Research
Management of Atrial Fibrillation with Wolff-Parkinson-White Syndrome
- The management of atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome requires careful consideration of the potential effects of various antiarrhythmic drugs on the anomalous pathway and the ventricular rate 2.
- Procainamide and Ajmaline are considered the most effective drugs for managing AF in patients with WPW syndrome, as they can cause transient complete block in the accessory pathway and reduce the ventricular rate 2.
- Lidocaine may also be effective in reducing the ventricular rate, although it is less effective than Procainamide and Ajmaline 2, 3.
- Amiodarone may slow the ventricular rate, but it is not reliable and can increase the ventricular rate in some cases 2, 4.
- Digitalis is not suitable for managing AF in patients with WPW syndrome, as it can increase the ventricular rate by decreasing the effective refractory period of the anomalous pathway 2.
- Verapamil, beta-blockers, and other drugs that influence only the A-V node are ineffective in managing AF in patients with WPW syndrome and may even be contraindicated, as they can enhance conduction of atrial fibrillation and predispose to ventricular fibrillation 2, 4, 5.
- Propranolol may slow the ventricular rate in some patients with WPW syndrome and AF, but it should not be used if most QRS complexes during AF are preexcited, as it can increase the ventricular rate 4.
Drug Choices for Atrial Fibrillation
- The choice of antiarrhythmic drug for AF depends on various factors, including the underlying heart condition, the presence of structural heart disease, and the potential for proarrhythmic effects 6.
- Class IC antiarrhythmic drugs are considered to have a low proarrhythmic risk and are often used as first-line agents for AF, although they should be avoided in patients with hypertrophied hearts or conditions with impaired cell contact 6.
- Amiodarone has a low proarrhythmic risk but can produce bradyarrhythmias and toxicity, and its use should be carefully considered 6.
Potential Risks and Complications
- The use of certain antiarrhythmic drugs, such as Verapamil, can enhance conduction of atrial fibrillation and predispose to ventricular fibrillation in patients with WPW syndrome 5.
- Fatal ventricular fibrillation has been reported in patients with WPW syndrome and AF who received Verapamil, highlighting the importance of careful drug selection and monitoring 5.