Remnants of right venous valve in utero and early postnatal life. Case report and literature review

During fetal life the right valve of the sinus venosus directs oxygenated blood from the inferior vena cava to the left atrium through the foramen ovale, until the regression of the right valve which usually occurs within the 15th week of pregnancy. Incomplete regression of the right venous valve in varying degrees can lead to different types of remnants such as the Eustachian valve, the Chiari Network and Cor Triatriatum Dexter. Prenatal diagnosis of remnants of right venous valve has only rarely been reported in the literature. We present a case of prenatal diagnosis of Chiari Network associated with severe tricuspid regurgitation, further complicated by tachyarrhythmia and signs of fetal heart failure with the appearance of abundant pleural and ascitic effusion. A cesarean section was performed at 32 weeks. After 48 h of life, because of persistence of atrial flutter, an electrical cardioversion was performed. The physical examination 7 months after being discharged showed a normal growth, good condition and persistence of mild tricuspid regurgitation. We also reviewed the available evidence on persistent right venous valve diagnosed in utero or early postnatal life. In conclusion we believe that prenatal recognition is helpful in planning fetal surveillance identifying those newborns at risk of dyspnea, cyanosis or neonatal heart failure.