Multiple mechanisms of tachycardias in a patient with the Wolff-Parkinson-White syndrome.

In a patient with the Wolff-Parkinson-White Syndrome we observed atrial fibrillation and three distinct paroxysmal re-entrant tachycardias. Intracardiac electrograms obtained during the tachycardias showed the mechanisms to be A-V nodal, accessory pathway and sinus node re-entry. When P wave morphology, R-P relationship and QRS configuration are considered, it is illustrated how these four tachyarrhythmias may be successfully diagnosed on the surface electrocardiogram. The therapeutic implications of multiple arrhythmias with different mechanisms in the Wolff-Parkinson-White Syndrome are discussed.