Abstract
We present a clinical case of the association of CCHB and HLHS in a newborn. The etiological relation between these two pathologies is unclear. According to the literature data, 70–90% of isolated CCHB are caused by maternal anti-Ro and anti-La antibodies, which cross the placenta and lead to fibrosis of the AV node or occur due to genetic defects, such as mutations in the SCN5A gene. Other theories suggest that compromised coronary blood flow in late fetal life could be a cause of CCHB, as the AV-node artery is the first and longest inferior septal branch of the right (90%) or left (10%) coronary artery, arising from U- or V-shaped segment of the corresponding artery at the level of the crux cordis. In our case, the level of maternal auto-antibody titers was unknown. It is possible that the heart block could be linked to the structural heart defect – HLHS, which could be the cause of hypoperfusion of AV node in fetal life. Only two similar cases of such combination are described in the literature.