INTRA-UTERO DIAGNOSIS OF ANOMALOUS RIGHT-VENTRICULAR MUSCLE BUNDLES IN ASSOCIATION WITH A VENTRICULAR SEPTAL-DEFECT - A CASE-REPORT

The morphology and natural history of anomalous right ventricular musc le bundles (ARVMB) have been described in a number of postnatal studie s. Whether this is a congenital or acquired cardiac lesion remains obs cure. A fetal echocardiogram performed in a 32-week gestation mother s howed a large ventricular septal defect and anomalous right ventricula r muscle bundles, which were easily appreciated at the ostium-infundib ular level. The diagnosis was confirmed postnatally and at 6 months of age the child underwent surgical repair. This report documents the pr esence of ARVMB in a fetus, at a time when hemodynamics cannot explain the development of right ventricular muscle bundles. It suggests that at least, the morphologic substrate for this disease is congenital.