Atrioventricular situs concordance with atrioventricular alignment discordance: Fetal and neonatal echocardiographic findings

Fetal echocardiography can reliably assess visceroatrial situs, ventricular morphology, and atrioventricular and ventriculoarterial alignments. The echocardiographic findings of this case were consistent with visceroatrial situs splitus, atrioventricular alignment discordance, and ventriculoarterial alignment concordance. This arrangement is almost always associated with ventricular inversion, or Llooped ventricles, and has therefore been widely referred to as isolated ventricular inversion. Rarely, as in this report, the arrangement may be associated with D-looped ventricles. Fetal and neonatal echocardiography may distinguish situs concordance with atrioventricular alignment discordance from isolated ventricular inversion in situs solitus by the presence, in the former, of superior-inferior ventricles,5 an anterior right ventricle, and a tricuspid valve that is anterior and to the right of the pulmonary valve, consistent with D-looped ventricles.2,5