Left Frontal Lobe Cardioembolic Stroke as a Co-presentation of Bicuspid Aortic Valve With Severe Stenosis and a Basal Interventricular Septal Aneurysm in a Young Female Patient.

Bicuspid aortic valve (BAV) and interventricular septum (IVS) aneurysms are common congenital heart defects affecting 1.3% and 0.3% of the population, respectively. The coexistence of membranous types of IVS aneurysm and BAV is even rarer. We report a case of a 48-year-old woman with a history of BAV and severe aortic stenosis who had a seizure in a grocery store and was brought to the emergency department (ED). An MRI of the brain without contrast revealed a left frontal lobe acute lacunar infarct, suggestive of embolic origin. A transesophageal echocardiogram confirmed a basal IVS aneurysm measuring 12.2 mm × 16 mm without intracardiac shunting or thrombi. We diagnosed her with cardioembolic stroke as a complication of BAV and IVS aneurysm and initiated anticoagulation as she did not qualify for surgical intervention. This report emphasizes that IVS aneurysms associated with BAV, although often asymptomatic, may cause adverse outcomes such as cardioembolic stroke. Therefore, timely detection by non-invasive imaging, including echocardiography, CT scans, and MRI, and appropriate intervention are essential to improving health outcomes and survival.