CLINICAL-SIGNIFICANCE OF MATERNAL ANTI-RO SS-A ANTIBODIES IN CHILDRENWITH ISOLATED HEART-BLOCK/

Objectives. We studied 30 consecutive children with isolated heart blo ck to assess the clinical impact of the presence of maternal anti-Ro/S S A antibodies for isolated heart block. Background. Isolated heart bl ock in children, often associated with maternal autoimmune disease lea ding to anti-Ro/SS-A auto antibody production, is an infrequent but po tentially lethal disorder. Methods. Thirty children with isolated hear t block were studied with respect to medical history and electrocardio graphic (ECG) analysis. The presence of anti-Ro/SS-A antibodies was de termined in the maternal serum. We also examined the ECGs of all broth ers and sisters of the patients for conduction abnormalities. Results. Twenty one of the 30 children had an anti-Ro/SS-Apositive mother (gro up A); the other 9 children had an anti-Rol SS-A-negative mother (grou p B). Comparison of the clinical data from both mothers and children r evealed that these two groups differed significantly with respect to t he following: Prenatal diagnosis and obstetric complications occurred more often in group A, whereas progression to complete block, QRS widt h >0.08 s, premature ventricular contractions and ventricular standsti lls >4.5 s occurred more often in group B. In addition, mothers of chi ldren in group A reported more spontaneous abortions. All siblings of children in groups A and B had normal ECGs, excluding a subclinical fo rm of heart black. Conclusions. Two types of heart block can be recogn ized: Congenital heart block is associated with maternal anti-Ro/SS-A antibodies and numerous obstetric and neonatal complications. It is di agnosed prenatally or at birth and is usually complete at onset and pr obably has a substantial recurrence risk. Heart block that is acquired later in life is not associated with maternal autoimmunity and has no risk for recurrence. It often presents as a partial block but progres ses to complete block in time.