Lidocaine in Wolff-Parkinson-White syndrome with atrial fibrillation.

Atrial fibrillation in the Wolff-Parkinson-White syndrome may be life-threatening because of the extremely rapid ventricular rates that can occur over the accessory pathway. An 18-year-old man with Wolff-Parkinson-White (type B) syndrome developed episodes of syncope due to atrial fibrillation. In studies during hospitalization the administration of lidocaine immediately slowed the ventricular response by abolishing antegrade conduction over the accessory pathway. The role of lidocaine and other antiarrhythmic drugs in the management of arrhythmias in the Wolff-Parkinson-White syndrome is discussed.