Perinatal Stroke and Cor Triatriatum Sinister: A Case Report.

Cor triatriatum sinister (CTS) is a rare congenital heart defect characterized by a fibromuscular membrane dividing the left atrium. Though often asymptomatic in incomplete forms, CTS has been associated with thromboembolic events. We describe a case of a female child with a history of perinatal stroke presenting with right hemiparesis. Prenatal imaging suggested lateral ventricle asymmetry and localized hemorrhage. Postnatal development was mostly normal until gait abnormalities emerged at 18 months. Neuroimaging confirmed left-sided brain injury consistent with a past vascular insult. Cardiac evaluation revealed non-obstructive CTS with no signs of hemodynamic compromise. Although a direct causal relationship could not be confirmed, the identification of CTS in a cryptogenic perinatal stroke case raises the possibility that subtle atrial anomalies may contribute to fetal thromboembolic events. This case reinforces the importance of comprehensive cardiac evaluation in perinatal strokes and illustrates a favorable neurodevelopmental outcome with early multidisciplinary intervention.