Intrauterine and perinatal management of complete atrioventricular block in the fetus.

PURPOSE: To report the experience of one of the most severe fetal rhythm disturbances, the complete atrioventricular block. METHODS: Descriptive study of 14 fetuses diagnosed and monitored at the Fetal Cardiology Unit, from January, 1991 to August, 1995. RESULTS: Fourteen cases of complete AV block were identified during the study period, with post-conceptional age between 22 and 38 weeks at the moment of diagnosis. Twelve cases were referred to the Fetal Cardiology Unit because of low heart rate during obstetric examination. Eight fetuses showed complete AV block without evidence of structural heart disease; maternal collagen tissue disease was diagnosed in three of these cases. Four neonates were discharged from the hospital, two of them with a permanent pacemaker, one with complete AV block but no pacemaker and the fourth with sinus rhythm. The remaining seven neonates presented with severe heart failure leading to death despite treatment. CONCLUSION: Complete AV block is a rare fetal condition, but carries a high morbidity and mortality. A several treatment techniques have been suggested to improve monitoring and survival of these patients, particularly in utero.