Congenital complete atrioventricular block in the early pediatric population.

Congenital complete atrioventricular block (CCAVB) is a rare potentially lethal disease with an estimated incidence of 1 every 15.000 to 20.000 live born infants. In structurally normal hearts two kinds of congenital heart block can be identified: one usually diagnosed in utero associated with the circulating maternal anti-SS-A/Ro and anti-SS-B/La antibodies, the other kind is detected later in the neonatal period or during the infancy or childhood and present no clear relation with maternal antibodies. Nowadays, the diagnosis can be made in utero as early as between week 16 and 28 of gestation by foetal echocardiography. The mortality in isolated CCAVB is estimated between 8 and 16% and between 4 and 8% in children and adults. The mortality and morbidity of patients diagnosed outside the neonatal period is significantly lower than those with a in utero diagnosis. Risk factors for worse outcome in CCAVB are the foetal diagnosis, the presence of hydrops fetalis, delivery at 32 weeks gestation, and a ventricular rate