True about Ebstein anomaly is?

ANSWER: (B) Right atrial dilatationREF: Nelsons 18thed ch: 430.7Ebstien's anomaly is a cyanotic heart disease with decreased pulmonary flow Pathophysiology:Characterized by a downward displacement of the tricuspid valve into the right ventricle, due to anomalous attachment of the tricuspid leaflets, the Ebstein tricuspid valve tissue is dysplastic and results in tricuspid regurgitation. The abnormally situated tricuspid orifice produces an "atrialized1' portion of the right ventricle lying between the atrioventricular ring and the origin of the valve, which is continuous with the RA chamber.EBSTEIN ANOMALYThe right ventricle is thus divided into two parts by the abnormal tricuspid valve: the 1st, a thin-walled "atrialized" portion, is continuous with the cavity of the right atrium; the 2nd, often smaller portion consists of normal ventricular myocardium.Often the right ventricle is hypoplastic.The right atrium is huge, and the tricuspid valve is generally regurgitant, although the degree is extremely variable.At times, right ventricular function is so compromised that it is unable to generate enough force to open the pulmonary valve in systole, thus producing "functional" pulmonary atresia.Some infants have true anatomic pulmonary atresiaThe increased volume of right atrial blood shunts through the foramen ovale to the left atrium and produces cyanosis.Clinical manifestations:Although the clinical manifestations are variable, some patients come to initial attention because of eitherProgressive cyanosis from right-to-left atrial shuntingSymptoms due to tricuspid regurgitation and RV dysfunctionParoxysmal atrial tachyarrhythmias with or without atrioventricular bypass tracts ("WPW" syndrome).Diagnostic findings by two-dimensional echocardiography include the abnormal positional relation between the tricuspid and mitral valves with abnormally increased apical displacement of the septal tricuspid leaflet. Tricuspid regurgitation is quantitated by Doppler examination.Surgical approaches include prosthetic replacement of the tricuspid valve when the leaflets are tethered or repair of the native valve.