[Syncope in a 16-year-old young man during a football match]

A case is reported of a previously healthy 16-year-old boy who developed a rapid atrial fibrillation following a minor thoracic impact. This tachyarrhythmia resistant to several drugs responded immediately to administration of flecainide. The restoration of sinus rhythm led to diagnosis of type A Wolff-Parkinson-White syndrome.