What should be avoided in the treatment of stable Wolff-Parkinson-White syndrome?

In the treatment of stable Wolff-Parkinson-White (WPW) syndrome, the use of AV node blockers should be avoided because they can lead to increased conduction through the accessory pathway, which may result in a rapid ventricular response or even degeneration into ventricular fibrillation. In patients with WPW, the presence of an accessory pathway allows for bypassing the normal conduction system, leading to reentrant tachycardias. When AV node blockers such as beta-blockers, calcium channel blockers, or digoxin are administered, they can facilitate conduction through the accessory pathway, worsening the patient's condition.

Other management strategies, such as vagal maneuvers, procainamide, and amiodarone, can be appropriate. Vagal maneuvers work by increasing parasympathetic tone to pace the heart and potentially interrupt reentrant circuits. Procainamide is effective because it acts as a Class IA antiarrhythmic that not only slows conduction in the atria but also in the accessory pathway. Amiodarone, while a Class III antiarrhythmic that primarily works by prolonging the action potential, can be used with caution, as it does not preferentially increase conduction through the accessory pathway as much as other agents.