Dichorionic Diamniotic Twin Pairs with Complex Congenital Heart Disease.

Complex congenital heart disease (CHD) in each of dichorionic diamniotic (DiDi) twin pairs is extremely rare and has not been well characterized. Four DiDi twin pairs were included in this multi-institutional case series. The congenital cardiac abnormalities noted included tetralogy of Fallot (ToF) with pulmonary atresia and collaterals (n = 1), ToF with absent pulmonary valve (n = 1), ToF (n = 2), discontinuous right pulmonary artery (RPA) (n = 1), tricuspid atresia (TA) with normally related great arteries and pulmonary valve stenosis or atresia (n = 2) and coarctation of aorta (CoA) with bicuspid aortic valve (BAV) and borderline left-sided structures (n = 1). Genetic testing was obtained on seven of the eight twins but did not reveal any causal abnormality. A comprehensive review of literature yielded another 8 DiDi twin pairs with complex CHD. The CHD noted in these twin pairs included ToF (n = 2), CoA (n = 4), corrected transposition of great arteries (ccTGA) (n = 2), truncus arteriosus (n = 2), complete common atrioventricular canal (CCAVC) (n = 2), hypoplastic left heart syndrome (HLHS) (n = 2), Shone's complex (n = 1), and hypoplastic right heart syndrome (HRHS) (n = 1). Limited genetic testing was obtained on 4 of these twins and revealed trisomy 21 in a twin pair. Conotruncal abnormalities (42%), CoA (21%), and abnormalities of the right ventricle, the right ventricular outflow tract and pulmonary arteries (17%) are more prevalent in DiDi twins with complex CHD. Clustering of these abnormalities suggests a possible genetic basis; however, genetic testing was obtained on eleven of the twins, and except for trisomy 21 in a twin pair both of whom had CCAVC, did not reveal any causal abnormality. A major direct genetic contribution is therefore unlikely and like other CHD, the underlying etiopathological basis is likely multifactorial.

Prenatal Diagnosis of Isolated Atrioventricular Discordance and Ventriculoarterial Concordance and Double-Outlet Right Ventricle in Situs Inversus: Case Report and Review of the Literature.

Atrioventricular (AV) discordance and ventriculoarterial (VA) concordance in the setting of visceral situs inversus are one of the rarest forms of cardiac malformations. To our knowledge, this is the first reported case of prenatal diagnosis of such rare cardiac anatomy in association with double-outlet right ventricle on fetal echocardiography. The physiology of this cardiac anomaly is similar to that of transposition of the great arteries, and the best surgical option is the atrial switch operation.

Chiari Network Associated with Hypoxemia in a Neonate: Case Report and Review of the Literature.

Chiari network is an embryonic remnant of the right sinus venosus. It appears as a thin, fenestrated membrane attached to two or more regions within the right atrium. Usually, a Chiari network has a benign course; however, rare complications associated with a Chiari network have been reported. We present the case of a neonate with hypoxemia and a Chiari network protruding into the right ventricular inflow tract associated with right-to-left shunting across the patent foramen ovale throughout the cardiac cycle. We noted spontaneous improvement after 3 weeks of life.

A Rare Report of Hypoplastic Coronary Arteries and Pulmonary Veins: A Case Report and Review of the Literature.

Congenital coronary artery anomalies are estimated to affect about 1% of the general population. Hypoplastic coronary artery disease is an uncommon subset associated with significant mortality regardless whether another major cardiac anomaly is present. In this case report, we present an extremely rare case of an infant with hypoplastic coronary artery disease and hypoplastic pulmonary veins. A literature review pertinent to the clinical findings is also contained herein.