COEXISTENCE OF ATRIOVENTRICULAR-BLOCK AND WOLFF-PARKINSON-WHITE-SYNDROME IN CHILDREN

Coexistence of atrioventricular block and Wolff-Parkinson-White syndro me is uncommon, but may occur in children, particularly with certain c ongenital heart defects. Our study describes 5 children who had pre-ex citation and underlying disturbance of atrioventricular conduction All of these patients had structural heart defects, consisting of discord ant atrioventricular connections in three, double inlet left ventricle in one, and a ventricular septal defect associated with straddling of the tricuspid valve in the other. In 4 of the patients, the presence of atrioventricular block was initially masked by the pre-excitation. When the conduction through an accessory pathway is lost, the child ma y be left with atrioventricular block, which is poorly tolerated in th e setting of complex cardiac anatomy. Awareness of this association of Wolff-Parkinson-White syndrome and atrioventricular block is importan t in understanding the natural history and the management of children with congenital heart defects that are associated with tenuous atriove ntricular conduction.