P-Wave Changes Associated with Chiari Network in the Right Atrium

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.

Prominent prolapsing Chiari network: presentation and prognosis in paediatric patients

Chiari network is an infrequently visualized web-like structure in the right atrium that is usually thin and small. Rarely, it can be prominent and elongated with protrusion into the right ventricle during diastole and complications have been reported. Thirty-eight patients (median age 2.5 years) with prolapsing Chiari network were identified and associated cardiac abnormalities documented. Echocardiographic right and left heart parameters were measured and compared to normative data. At presentation, the extent of Chiari network prolapse below the tricuspid annulus was 9.1 ± 3.5 mm (mean ± standard deviation), mean pulmonary valve annulus diameter z-value was reduced (-0.91 ± 0.64), and mean aortic valve z-value was enlarged (+0.97 ± 0.87). Fourteen patients exhibited no other cardiac abnormality. Eight were noted to have atrial septal defects, eight demonstrated supraventricular dysrhythmias, six had mild to moderate tricuspid valve regurgitation, and one patient each had an atrial septal aneurysm, severe pulmonic valve stenosis, small perimembranous ventricular septal defect, bicuspid aortic valve, and mild right upper pulmonary vein stenosis. Fourteen patients (37%) were seen in follow-up from 1 to 8.5 years later (median 3.2 years). During that time, the magnitude of prolapse across the tricuspid valve decreased by up to 7 mm (median 2 mm). Interventions were required in three patients, but many associated cardiac abnormalities resolved spontaneously with growth. Thus, the presence of a prolapsing Chiari network has a substantial risk of associated CHDs. However, the extent of Chiari network prolapse gradually decreases and many related abnormalities resolve during growth.