Perinatal outcome of fetus with isolated congenital second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies.

OBJECTIVE: We determined the perinatal outcomes of fetuses with isolated congenital second degree atrioventricular block detected in utero and born to mothers seronegative for anti-SSA/Ro-SSB/La antibodies.

METHODS: Isolated second degree atrioventricular block was defined as second degree atrioventricular block detected in utero without the accompanying structural cardiac anomaly, tachyarrhythmia, non-conducted premature atrial beats or long QT syndrome. We review our own cases and search from Medline using keywords such as atrioventricular block, arrhythmia, bradycardia and congenital to collect cases of congenital isolated second degree atrioventricular block.

RESULTS: Two cases were from our institution and five cases from a Medline search; in total seven cases of isolated second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies were analyzed. Six of the seven fetal arrhythmias reverted to sinus rhythm by delivery and did not recur during the follow-up period. The prognosis of the fetus with isolated second degree atrioventricular block without maternal anti-SSA/Ro-SSB/La antibodies is better than that of the fetus with maternal anti-SSA/Ro-SSB/La antibodies or the fetus of congenital long QT syndrome with second degree atrioventricular block detected in utero.

CONCLUSION: The fetus with isolated congenital second degree atrioventricular block carries a good prognosis in the absence of maternal anti-SSA/Ro-SSB/La antibodies.