A Rare Congenital Triad: Ebstenoid Tricuspid Valve, Giant Right Atrial Aneurysm, and Atrial Septal Defect

Technical Summary: A Rare Congenital Triad of Ebstenoid Tricuspid Valve, Giant Right Atrial Aneurysm, and Atrial Septal Defect

Problem Statement
The paper addresses an exceptionally rare congenital cardiac triad comprising an Ebstenoid tricuspid valve anomaly, a giant right atrial aneurysm (RAA), and an ostium secundum atrial septal defect (ASD). While Ebstein anomaly is a known congenital malformation involving apical displacement of the tricuspid valve leaflets, the "Ebstenoid" variant is a distinct, less common morphological entity characterized by abnormal leaflet morphology without the classical apical displacement or right ventricular atrialization. The coexistence of this specific variant with a massive, aneurysmal right atrium and an ASD is rarely documented. Patients with such severe right-sided volume overload face significant risks, including atrial arrhythmias, thromboembolic events, progressive right ventricular (RV) dysfunction, and heart failure. The clinical challenge lies in accurately delineating the complex anatomy to determine operability and planning a surgical strategy that addresses the valve pathology, the shunt, and the aneurysmal dilation simultaneously.

Methodology
This study presents a single case report of a 15-year-old female patient presenting with progressive exertional dyspnea (NYHA class II) and palpitations. The diagnostic approach relied on a comprehensive multimodality imaging strategy:

• Transthoracic Echocardiography (TTE): Used to identify severe low-pressure tricuspid regurgitation, the specific morphology of the tricuspid valve (elongated anterior leaflet, tethered septal leaflet without apical displacement), the giant right atrium (9.0 × 9.8 cm), and the ASD with left-to-right shunting.
• Four-Dimensional Echocardiography: Employed to provide a detailed assessment of tricuspid valve leaflet motion and coaptation.
• Cardiac Computed Tomography (CT): Utilized to confirm the dimensions of the aneurysmal right atrium (9.3 × 9.4 cm, area 78 cm²), rule out intracavitary thrombus, and exclude other associated congenital anomalies.
• Cardiac Catheterization: Performed to measure pulmonary artery pressures, which were found to be approximately one-third of systemic pressure, confirming favorable pulmonary vascular resistance and surgical operability.

Following multidisciplinary heart team discussion, the patient underwent elective surgical correction via median sternotomy and cardiopulmonary bypass. The surgical procedure involved:

1. Native Tricuspid Valve Repair: Mobilization of the anterior leaflet, release of tethering where feasible, and annuloplasty to restore leaflet coaptation.
2. ASD Closure: Surgical closure of the secundum defect.
3. Right Atrial Reduction Atrioplasty: Excision of excess aneurysmal right atrial tissue to reduce atrial volume.

Key Results

• Intraoperative Findings: Inspection confirmed a massively aneurysmal right atrium with a thinned wall and severe malcoaptation of the tricuspid valve due to the elongated anterior and tethered septal leaflets. Notably, right ventricular atrialization was minimal.
• Immediate Postoperative Outcome: Intraoperative transesophageal echocardiography confirmed satisfactory valve competence, intact ASD closure, marked reduction in right atrial size, and preserved RV function. The postoperative course was uneventful, with the patient maintaining sinus rhythm and no conduction disturbances.
• One-Year Follow-up: The patient remained asymptomatic (NYHA class I). Echocardiography demonstrated sustained reduction in right atrial size, stable tricuspid valve repair with only trivial residual regurgitation, preserved RV function, and no recurrence of aneurysmal dilatation.

Key Contributions
The paper contributes to the medical literature by documenting a rare combination of three distinct congenital pathologies that are seldom reported together. It highlights the utility of multimodality imaging—specifically the combination of 4D echocardiography and cardiac CT—in defining complex anatomical details that are critical for surgical planning. The case demonstrates that a combined surgical approach (valve repair, ASD closure, and atrial reduction) is feasible and effective even in the presence of a giant right atrial aneurysm. Furthermore, it reinforces the preference for native valve repair over replacement in young patients to preserve long-term RV function.

Significance and Claims
The authors claim that this case underscores the importance of early recognition and timely surgical intervention in complex congenital tricuspid valve anomalies to prevent irreversible right-sided heart failure and arrhythmic complications. The successful outcome emphasizes that individualized surgical planning based on comprehensive anatomical assessment can yield excellent clinical and echocardiographic results. The paper notes that while the one-year follow-up is promising, continued surveillance is necessary to evaluate the long-term durability of the valve repair and the occurrence of late arrhythmias, acknowledging the limitation of the relatively short follow-up period in this single-case report.