[Follow-up studies in 64 patients with WPW syndrome after electrostimulation]

In 65 out of 79 patients with WPW syndrome who had extensive electrostimulation studies, a follow-up evaluation (mean follow-up period 2.5 years) was performed. The patients were divided into 2 groups: Group 1: No therapy or therapy only during tachycardia. Group 2: Continuous oral drug therapy. There was no difference of antegrade and retrograde refractory periods, but there was a significant difference in the initiation of tachycardias. In group 1, the typical reentry tachycardia using the AV node antegradely and the accessory pathway retrogradely was predominant, while in group 2, complex arrhythmias (atrial fibrillation + reentry tachycardia, tachycardias using the accessory pathway in both directions, reentry tachycardia + AV-nodal tachycardia, isolated atrial fibrillation) during electrostimulation could be induced. all except 1 patient in whom no tachycardia could be initiated were in group 1 (statistically significant difference). Thus the type of tachycardia which can be initiated during electrostimulation is a better predictor for the condition in the follow-up period than the refractory period. As concomitant disease there were 4 cases with Ebstein disease (2 had additional mitral valve prolapse syndrome) and 3 cases with mitral valve prolapse syndrome. 3 of the 4 patients with Ebstein disease were in group 2. 1 of the 64 patients died during the follow-up period suddenly, but the cause of death is not known and possibly due to medical therapy. The mortality in a non-selected group of patients with WPW syndrome seems to be very low.