A rare congenital triad: ebsteinoid tricuspid valve, giant right atrial aneurysm, and atrial septal defect.

BACKGROUND: Ebstein anomaly is a rare congenital malformation of the tricuspid valve, accounting for less than 1% of all congenital heart diseases. Ebsteinoid anomaly is an uncommon morphological variant characterized by abnormal tricuspid valve leaflet morphology without the classical apical displacement of the septal leaflet seen in Ebstein anomaly. The coexistence of an Ebsteinoid anomaly, giant right atrial aneurysm (RAA), and atrial septal defect (ASD) is exceptionally rare. CASE PRESENTATION: A 15-year-old girl presented with progressive exertional dyspnoea (New York Heart Association [NYHA] class II) and intermittent palpitations. Chest radiography demonstrated marked cardiomegaly. Transthoracic echocardiography revealed a giant right atrium, severe low-pressure tricuspid regurgitation, an ostium secundum ASD, and an Ebsteinoid tricuspid valve with an elongated anterior leaflet and tethered septal leaflet, without apical displacement or right ventricular atrialization. Four-dimensional echocardiography and cardiac computed tomography confirmed the anatomical findings. Cardiac catheterization demonstrated pulmonary artery pressures approximately one-third of systemic pressure, confirming operability. The patient underwent successful tricuspid valve repair, ASD closure, and right atrial reduction atrioplasty. At one-year follow-up, she remained asymptomatic (NYHA class I) with preserved right ventricular function and only trivial residual tricuspid regurgitation. CONCLUSION: This case describes an exceptionally rare combination of Ebsteinoid tricuspid valve anomaly, giant right atrial aneurysm, and an ostium secundum ASD. Multimodality imaging was essential for accurate anatomical delineation and surgical planning. Early surgical correction resulted in excellent clinical and echocardiographic outcomes, underscoring the importance of timely intervention in complex congenital tricuspid valve anomalies.