The hidden unicuspid: Recurring aortic stenosis post-valvuloplasty from a unicuspid aortic valve masquerading as bicuspid.

Unicuspid aortic valves (UAV) account for 0.2 % of cardiac valvular disorders and present with early-onset aortic stenosis (AS) during adolescence or early adulthood. We present a case of a 17-year-old male with recurring AS. He was diagnosed with bicuspid aortic valve (BAV) two years previously and treated with balloon valvuloplasty, which relieved symptoms before that. Multimodality imaging work-up revealed the precise morphology of UAV, consistent with the surgical findings. The patient received a St. Jude mechanical valve (St Paul; MN, USA) which resolved his symptoms. A thorough radiologic evaluation is therefore required for the accurate diagnosis of UAVs. While 2-dimensional (2D) transthoracic echocardiography (TTE) often constitutes the initial modality for evaluating UAVs, 3D-TTE, transesophageal echocardiography, and cardiac computed tomography are used as confirmatory diagnostic tools. Balloon valvuloplasty reports good outcomes in BAV but is associated with an increased rate of symptom recurrence, repeated surgical procedures, and higher mortality in UAVs, underscoring the importance of an accurate pre-operative diagnosis. Learning objectives: 1.Unicuspid aortic valve (UAV) should be considered in the differential diagnosis of severe aortic stenosis during childhood.2.3D-transthoracic echocardiogram, transesophageal echocardiogram, and cardiac computed tomography (CT) can confirm the diagnosis of a UAV.3.Cardiac CT can additionally assess for accompanying abnormalities of the great vessels in UAV patients.4.Balloon valvuloplasty reports good outcomes in bicuspid aortic valve but is associated with an increased rate of symptom recurrence in UAV patients.