Proposal for a new definition of congenital complete atrioventricular block

Abstract

The classic old definition of congenital heart block by Yater (1929) is still generally accepted: ‘Heart block establishedin a young patient. There must be some evidenceof the existenceof the slow pulse at a fairly early age and absence of a history of any infection which might cause the condition after birth: notably diphtheria, rheumatic fever, chorea and congenital syphilis’. However, other definitions are used. We systematicallyreviewed 1825 cases from 38 separatestudies. We conclude that complete AV blocks detected in utero in the absence of structural abnormalities differ from blocks detected later in life with respect to pathogenesis (they are generally associated with maternal anti-Ro/SSA antibodies), poorer childhood prognosis, increased risk of developing late-onset dilated cardiomyopathy, different maternal clinical features and increased risk of recurrence in future pregnancies.For these reasons we propose a new modern definition of congenitalcomplete AV block which might be acceptable to cardiologists, rheumatologists, pediatricians and obstetricians: ‘an AV block is defined as congenital if it is diagnosed in utero, at birth or within the neonatal period (0-27 days after birth)’.