RESUMO
Background: Tricuspid valve agenesis is an exceptionally rare congenital cardiac disease characterized by the incomplete formation or complete absence of one or more tricuspid leaflets. It is commonly diagnosed during childhood due to the development of heart failure symptoms. Case summary: We report the case of a 62-year-old woman admitted for a worsening of heart failure symptoms (New York Heart Association functional Class IV at admission). A standard transthoracic echocardiogram was performed, which showed severe right heart dilatation and severe tricuspid regurgitation. A three-dimensional echocardiogram revealed the absence of the posterior tricuspid leaflet. The patient underwent an uncomplicated surgical bioprosthetic valve replacement with a favourable outcome and partial recovery of right ventricular function. In our patient, valve repair was not favoured due to the additional mild hypoplasia of the anterior leaflet. The 3-month post-operative evolution of the patient was favourable, with significant symptom relief. Discussion: The diagnosis of tricuspid agenesis during adulthood is uniquely uncommon. A three-dimensional echocardiography can provide accurate pre-procedural insight into the valve anatomy, allowing surgeons to plan for either valve repair when the anatomy is suitable or valve replacement.