Incidence or Coincidence: Subaortic Membrane, Bicuspid Aortic Valve, and Aortic Root Dilatation in a Patient Presenting With Stroke.

Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation and is frequently associated with progressive aortopathy. Subaortic membrane, a discrete form of left ventricular outflow tract (LVOT) obstruction, is uncommon in adults and rarely coexists with BAV outside of complex congenital syndromes. The simultaneous presence of BAV, aortic root dilation, and a subaortic membrane represents an unusual anatomical constellation with important diagnostic and clinical implications. We present the case of a 49-year-old man with no known medical history who developed sudden, painless monocular vision loss and was diagnosed with left central retinal artery occlusion (CRAO). Neurovascular imaging revealed mild carotid atherosclerosis and incidental ascending aortic dilation. Transthoracic echocardiography (TTE) demonstrated a probable BAV, left atrial enlargement, and a suspected subaortic membrane with elevated LVOT gradients. Transesophageal echocardiography confirmed BAV morphology, mild aortic stenosis, and aortic root dilation measuring 4.2 cm, along with severe atherosclerotic plaque in the aortic arch, suggesting an embolic source. This case highlights the importance of comprehensive cardiac evaluation in patients with unexplained embolic events and expands the spectrum of structural abnormalities associated with BAV. Recognition of this rare triad is important for appropriate surveillance, risk stratification, and multidisciplinary management.