CONGENITAL COMPLETE HEART-BLOCK IN THE NEWBORN ASSOCIATED WITH MATERNAL SYSTEMIC LUPUS-ERYTHEMATOSUS AND OTHER CONNECTIVE-TISSUE DISORDERS

Congenital complete heart block, sometimes presenting with bradycardia before birth, is a rare clinical entity present in about one in 20,000 live births. Familial occurrence has been reported a number of times since the first description by Morquio (1901). In about 30% of cases there is another congenital abnormality, the most common of which is corrected transposition of the great arteries, but an association with other congenital anomalies has been reported. Of those cases with no associated abnormality, some probably result from abnormal development of the embryonic conducting system. It is possible that others result from disruption of the conducting system by some inflammatory process in utero, and there have been reports of an association between congenital complete heart block in the newborn and SLE in the mother. Four babies with complete heart block associated with maternal systemic lupus erythematosus (SLE) are described, together with a 5th baby whose mother has serological abnormalities only. One baby had a rapidly fatal outcome, one has required digoxin for heart failure, and the remaining 3 are asymptomatic but remain in complete heart block. Additional manifestations were present in 2 of them. The spectrum of neonatal abnormalities that may occur in association with maternal SLE and related connective tissue disorders is discussed, together with the possible causes and the prognosis. The authors conclude that congenital heart block is more common than had previously been appreciated.