Congenital alveolar capillary dysplasia with misalignment of pulmonary veins associated with hypoplastic left heart syndrome

Three full-term infants died in the first month of life with hypoplastic le ft heart syndrome (HLH) and persistent pulmonary hypertension (PPH). At pos tmortem examination, they were found to have alveolar capillary dysplasia w ith misalignment of pulmonary Veins (ACD with MPV). The association of HLH syndrome, and ACD with MPV with intestinal malrotation and/or obstruction, is unique. Decreased blood flow in the ascending aorta in fetuses with left outflow tract obstruction might cause vasoconstriction of pulmonary arteri oles to maintain cerebral perfusion. Vasoconstriction early during embryoge nesis might lead to decreased growth and development of alveolar capillarie s and pulmonary veins. This results in pulmonary hypertension, and the arte rial blood is forced to bypass the deficient capillary bed and can drain on ly via the anomalous bronchial veins.