[Congenital complete atrioventricular block in children: pathogenesis and clinical outcomes].

Congenital complete atrioventricular block (CCAVB) is induced by the placental transmission of maternal anti-SS-A/Ro and anti-SS-B/La antibodies during the second trimester of pregnancy where they cause inflammatory injury to the foetal heart. Anti-SS-A/Ro and anti-SS-B/La antibodies can be detected in most mothers of children with CCAVB. However, the chance of an antibody-positive woman giving birth to a child with CCAVB is 1-5% and the chance of this recurring is 16%. In addition to the maternal antibodies, foetal and environmental factors may also play a role in the pathogenesis. CCAVB is associated with high morbidity and mortality during the foetal and neonatal period. Pacemaker implantation is indicated in approximately 60% of these children, after the development of symptoms related to bradycardia, although the timing of this is controversial. The effectiveness of therapeutic intervention in the uterus has yet to be determined. A conservative approach is advisable with respect to the use of corticosteroids.