Clinical and electrophysiologic evolution of the Wolff-Parkinson-White syndrome in children: impact on approaches to management.

There is less certainty about the recommendations for radio-frequency ablation as a therapeutic option for Wolff-Parkinson-White syndrome in children as opposed to adults because of the different natural history and the age-related risks of ablation. To help decision-making, we evaluated the long term clinical evolution and electrophysiologic characteristics of pre-excitation in our series of children and young adults. We reviewed the clinical course of 109 patients below the age of 18 years who had been followed up over a period of 9+4 years, with a range from one to 27 years. This corresponded to 986 patient-years. We examined also the electrophysiologic data from 98 of those patients who underwent a transesophageal study. At the discovery of pre-excitation, 59% of patients were asymptomatic, while 29% developed supraventricular tachycardia during follow-up. The peak incidence of the onset of supraventricular tachycardia occurred during infancy. These patients had the highest incidence of subsequent spontaneous disappearance of the tachycardia (53%), such a favourable evolution being encountered in only 12% of patients in whom the abnormal rhythm first appeared after 12 years of age. Chronic medical treatment was required in 47% of patients, and proved completely effective in 45% of cases. The potential to induce atrial fibrillation, and the incidence pre-excitation considered to be high risk, with the shortest pre-excited RR interval equal to or less than 220 msec, was lowest in the group of patients aged less than 6 years of age, and highest in those older than 12 years of age (p <0.001). Pathways producing arrhythmia with high risk were more common in symptomatic (29%) than in asymptomatic patients (7%) (p<0.001). No mortality occurred. On the basis of our findings, we suggest that ablation should be avoided before the age of 5 or 6 years. Thereafter, the procedure should become the first line of treatment for symptomatic patients older than 12 years of age.