Anatomical features of congenital right atrial diverticulum on 3D-transoesophageal echocardiography.

A 9-year-old female was referred to our institution with a history of palpitations at rest. She had no comorbidities or history of cardiovascular disease. Previous electrocardiograms (ECGs) and 24 h Holter monitoring failed to record any arrhythmias. The physical examination revealed a blood pressure of 100/ 60 mmHg, pulse of 85 b.p.m., and normal findings on auscultation. The 12-lead ECG was normal for age and sex. A transthoracic echocardiogram revealed an abnormal chamber connected to the lateral wall of the right atrium consistent with a large congenital right atrial aneurysm/diverticulum. A transoesophageal echocardiogram was then performed (Panel A) along with 3D off-line reconstruction. Multiplane 3D views showed a large diverticulum connected to the free wall of the right atrium with a 1 * 1.5 cm orifice (Panel B–E) with several trabeculae consistent with septation within the diverticulum (Panel D). The patient was referred for surgery owing to the increased risk of supraventricular arrhythmias and thrombus formation. Surgical exploration confirmed all the echocardiographic findings (Panel F). Excision of the diverticulum and direct suture of the connecting orifice was then performed. The patient was discharged 7 days after surgery and remains asymptomatic at 6-month follow-up.