[Congenital complete atrio-ventricular block].

Congenital complete atrio-ventricular block is a rare condition, the result of an anatomical anomaly of the conduction pathways, or even the trans-placental passage of maternal antibodies causing fetal myocarditis with fibrosis of the conduction tissue. It is not clear whether AV block discovered later in childhood is really "congenital". Whatever the age of the child, the only treatment is pacemaker implantation. Cardiac failure and syncope are absolute indications for implantation. Children whose heart rate is below 50 beats per minute (bpm) represent a group at high risk of syncope or even sudden death and must be paced, even if asymptomatic. Moreover, certain patients with immunological complete AV block have cardiopathy and must also be paced. In our department, the route for pacing is epicardial in younger children, in practice weighing less than 10-15 kg, and endocavitary in older children. The choice is either double chamber pacing, which restores AV conduction initiated by the child's sinus, or ventricular pacing with activity-controlled heart rate. Although worrying complications have been described, such as venous thrombosis, infections related to repeated interventions, and delayed cardiomyopathy, the results of paediatric pacing are generally satisfactory and the great majority of children with congenital complete AV block lead a normal life.