Cor Triatriatum Sinister Presenting as Cardioembolic Stroke in a Young Woman

Cor triatriatum sinister is a rare congenital heart disease characterized by an additional fibromuscular membrane in the left atrium. Cardioembolic stroke is a rare complication of cor triatriatum sinister, especially among women. We hereby describe the case of an 18-year-old female patient, without a past medical history, presenting with cardioembolic stroke in the territory of the right posterior cerebral artery. During extensive diagnostic work-up, nonrestrictive cor triatriatum sinister and patent foramen ovale were diagnosed using transthoracic and transesophageal echocardiography. In clinical practice, it is important to identify congenital cardiac defects as potential substrates for cardioembolism in young patients. In our case, cor triatriatum sinister presenting as ischemic stroke was diagnosed, which is an uncommon finding, especially in young females. Determining the optimal management strategy for patients with cor triatriatum sinister complicated by cardioembolic stroke requires a multidisciplinary approach.