The majority of cases are detected in the foetal period during routine scanning. Foetal presentation is a predictor of poor outcome [9]. Foetal presentation depends on the severity of the tricuspid regurgitation and the association with other lesions such as pulmonary atresia. Massive right atrial dilatation with progressive enlargement of the right side of the heart is a common feature. Poor prognostic signs are the presence of heart failure (hydrops, ascites, pericardial and pleural effusions and polyhydramnios), tachyarrhythmia, massive right atrial enlargement from severe tricuspid insufficiency and absence of forward flow across the pulmonary valve (functional pulmonary atresia). The size of the right atrium is important in prognosis in this group; significant enlargement of the right heart impacts on foetal lung development with the development of pulmonary hypoplasia [10]. A number of prognostic scores have been developed to predict postnatal outcome such as the Celermajer index and the Simpson-Andrews-Sharland score, and although no single echocardiographic feature is consistent in predicting prognosis, a useful indicator is the flow pattern through the pulmonary artery during the first prenatal scan. Retrograde flow was strongly correlated with foetal or neonatal death, and anterograde flow predicted good outcome [11, 12].

Presentation in the neonatal period in the majority of cases is with right heart failure or cyanosis. Heart failure is a consequence of significant tricuspid regurgitation and right ventricular dysfunction. Cyanosis is a result of right to left shunting across the atrial septum due to severe tricuspid regurgitation.

Initial management in the neonatal period is to employ measures aimed at reducing the pulmonary vascular resistance to encourage forward flow across the pulmonary artery and reduce the amount of tricuspid regurgitation; the use of prostaglandins to maintain ductal patency and thereby improve pulmonary blood flow is encouraged. One needs to be aware however of the risk of developing a circular shunt with blood circulating via the ductus to the pulmonary arteries, through the pulmonary valve and from the right ventricle via the incompetent tricuspid valve to the RA and across the septal defect to the LA and returning to the LV. In these circumstances to stop this spiralling deterioration the prostaglandins would need to be discontinued. When the pulmonary vascular resistance starts falling and signs of pulmonary overcirculation develop, to further stabilise the circulation, ductal ligation may be necessary. Neonatal presentation with heart failure or cyanosis is a poor prognostic feature [13, 14].

Neonates with severe tricuspid regurgitation present early with heart failure and cyanosis. These babies will have a right to left shunt at the atrial level and in some cases may be duct dependant should there be absence of forward flow in the pulmonary artery (functional pulmonary atresia). The degree of tricuspid regurgitation is exacerbated by raised pulmonary artery pressures and the additional association with severe pulmonary hypoplasia. It is often impossible to achieve adequate ventilation. Thus, the cause of death is lung hypoplasia although the primary lesion is cardiac [15].

Cases of tricuspid valve dysplasia presenting for the first time as adults have been described [16, 17]. Adult presentation is due to increasing exercise intolerance and right heart failure. Many of these patients will have a history of atrial fibrillation related to right atrial dilatation. An important differential diagnosis at this age includes carcinoid disease and rheumatic heart disease. It is also important to exclude infective endocarditis in this patient group. Surgery is possible and is indicated for heart failure resistant to all medical treatment. This is performed by annuloplasty or by mechanical or bioprosthetic valve replacement [17].