[Wolff-Parkinson-White syndrome: two accessory pathways concealed conduction accompanied by enhanced AV node conduction (author's transl)].

The case report of a 40 years old female patient with Wolff-Parkinson-White syndrome and concealed conduction of the accessory pathways is presented. Endocardial mapping revealed two re-entry tachycardias with different rates and different sequences of retrograde atrial depolarisation. These accessory bypass tracts were accompanied by enhanced AV node conduction. -- Patients with multiple accessory pathways and enhanced AV node conduction appear to be a special group of WPW-syndrome in respect of life-threatening tachycardias.