Multiple accessory pathways: a combined electrophysiological and radionuclide study

Electrophysiological study in a patient with Wolff-Parkinson-White syndrome revealed multiple accessory pathways: Kent bundle and Mahaim nodoventricular and fasciculoventricular fibers. Radionuclide phase imaging disclosed two distinct ventricular activation sequences during sinus rhythm or slow atrial pacing and during fast atrial pacing. The third activation pattern could be recorded after injection of ajmaline, which abolished signs of preexcitation in the electrocardiogram. Phase image in combination with pacing and pharmacological interventions can, at least in some cases, detect complex preexcitation syndromes noninvasively.