[Wolff-Parkinson-White syndrome; important in childhood also].

In a cooperative, retrospective, study 120 children are reviewed with preexcitation pattern. 80 patients had tachycardias; 54 children were under 1 year, 49 under 3 months of age at their first attack. In 50% the preexcitation pattern disappeared in the first year of life, allthough intermittent preexcitation could be seen in some patients. In 12 patients a circusmovement tachycardia was proved on the surface ecg; in the group of 63 children with a tachycardia of unknown origin probably more may be caused by this mechanism. A beneficial effect of digoxin in childhood is noticed, with good response in 45 cases. A possible explanation for the difference in effect of digoxin during childhood and in adolescence is discussed.