Congenital atrioventricular block: histological aspects

Fetal manifestations of maternal anti-Ro and La antibodies - more than complete heart block

Complete heart block (CHB) is a potentially fatal condition occurring in approximately 1:10000 fetuses. Whilst it is well recognised that maternal anti-Ro and La antibodies are associated with fetal CHB, there are multiple other manifestations of fetal exposure to these autoantibodies which are not widely appreciated and rarely diagnosed. The importance of identifying affected fetuses lies in the significantly increased risk of recurrence in future pregnancies, and the potential for treatments which may modify this risk. This paper presents several cases to highlight the varying fetal presentations of maternal anti-Ro and La antibodies.

Role of calcium channels in congenital heart block

Congenital heart block (CHB) is a conduction abnormality that affects hearts of foetuses and/or newborn to mothers with autoantibodies reactive with the intracellular soluble ribonucleoproteins 48-kD La, 52-kD Ro and 60-kD Ro. CHB carries substantial mortality and morbidity, with more than 60% of affected children requiring lifelong pacemakers. Several hypotheses have been proposed to explain the pathogenesis of CHB. These can be grouped under three main hypotheses: Apoptosis, Serotoninergic and Ca channel hypothesis. Here, we discuss these hypotheses and provide recent scientific thinking that will most likely dominate the future of this field of research.

Atrioventricular block detected in fetal life: associated anomalies and potential prognostic markers

OBJECTIVES

To assess the spectrum of anomalies associated with fetal heart block and to identify possible prognostic markers.

METHODS

Retrospective review of all cases of second- or third-degree heart block identified in two tertiary referral centers in Germany (Bonn and Lübeck) and one in the USA (Baltimore).

RESULTS

Sixty fetuses with heart block were identified in the study period. Thirty-two had complex cardiac malformations, 31 of them associated with left isomerism. The outcomes of these fetuses were 22 terminations of pregnancy (TOP), three intrauterine fetal deaths (IUFD), three neonatal deaths (NND), two childhood deaths (CD) and there were two survivors. In 20 cases without complex cardiac malformations maternal antinuclear-antibodies were detected. Their outcomes were 2 TOP, 1 IUFD, 1 NND and 16 survived. The remaining eight cases had neither complex cardiac malformations nor associated maternal antibodies. Their outcomes were 1 TOP, 2 IUFD, 2 NND and 3 survived. After exclusion of terminated cases, hydrops as well as the presence of cardiac defects was significantly associated with non-survival (P < 0.01). The cardiothoracic circumference ratio was significantly higher in hydropic fetuses and significantly negatively correlated with survival in immune-mediated cases (P < 0.01). Atrial and ventricular frequencies and their evolution did not accurately predict fetal or neonatal outcome. Sympathomimetic treatment in seven cases was not associated with favorable fetal outcome in cases of hydrops or cardiac malformations.

CONCLUSIONS

The most important marker predicting adverse outcome in cases of heart block is fetal hydrops, followed by the association with complex cardiac malformations. Cases without cardiac malformations have a significantly better prognosis, especially in the absence of severe cardiomegaly.