Idiopathic Right Atrial Enlargement (Volume: 700 cc) in a Young Man: A Case Report

Idiopathic right atrial dilation is known as a congenital anomaly in the absence of obvious causes that produce right ventricular pressure or volume overload. Congenital giant right atrium can cause functional tricuspid regurgitation, arrhythmia, and rightsided heart failure. A massive Idiopathic Dilation of Right Atrium (IDRA) was reported in a 30-year-old man presented with intermittent palpitation and dyspnea on effort. Transthoracic echocardiography revealed huge right atrium leading to severe tricuspid regurgitation, moderate right ventricular enlargement with moderate dysfunction, and no evidence of other valvular heart diseases increasing the right ventricular pressure or volume, left to right shunt, and Ebstein anomaly. Cardiac Magnetic Resonance Imaging (MRI) confirmed the right atrial enlargement. The estimated right atrium volume by MRI was about 700 mL. With regard to the patient’s symptoms, he was scheduled for surgical treatment. The patient underwent partial surgical resection of the dilated right atrium wall and mechanical tricuspid valve replacement because the tricuspid valve was unrepairable on the operation table. Idiopathic right atrial enlargement is a very rare disease and may be easily confused with other anomalies that lead to right atrial enlargement, such as Ebstein anomaly. Hence, the probability of this pathology should be kept in mind when the usual etiologies of right atrial enlargement are excluded. Partial surgical resection of the dilated right atrium is an effective therapeutic option in symptomatic patients.