Prenatal diagnosis of isolated levocardia and a structurally normal heart: two case reports and a review of the literature.

Isolated levocardia (ILC) is a developmental abnormality involving an abnormal abdominal situs with a normal cardiac situs. This abnormality is especially rare when it is associated with a normal cardiac anatomy. The prenatal diagnoses of seven cases were reported in the English literature. This report presents two cases referred to the authors' echocardiography laboratory for maternal diabetes mellitus in case 1 and suspected dextrocardia in case 2. In both cases, ILC with a structurally normal heart was diagnosed prenatally. The child in the first case was found to have a normal inferior vena cava (IVC) prenatally. Postnatally, he was found to have intestinal malrotation with duodenal obstruction and multiple splenules. Interruption of the IVC was shown by abdominal ultrasound. The child in the second case was found to have an interrupted IVC with azygos continuation prenatally. Postnatally, intestinal malrotation with no evidence of intestinal obstruction or asplenia was detected. Neither of the cases had reported cardiac arrhythmias. Early diagnosis is crucial in these cases due to the high incidence of associated anomalies and potential life-threatening conditions. Management of patients with ILC is dictated by the associated anomalies. Long-term follow-up assessment is recommended for these patients to monitor the development of rhythm abnormalities.