Adult Presentation of Supracardiac Total Anomalous Pulmonary Venous Connection with Direct Drainage into the Superior Vena Cava.

We report the case of a woman in her late 30 s with longstanding cyanosis diagnosed with a rare supracardiac total anomalous pulmonary venous connection (TAPVC) draining directly into the superior vena cava (SVC). Her survival into adulthood was facilitated by a large, nonrestrictive atrial septal defect, and unobstructed pulmonary venous return, allowing functional compensation despite chronic hypoxemia. Echocardiography, cardiac catheterization, and computed tomography confirmed the anatomy and surgical feasibility. This case highlights this rare anatomic variant of TAPVC with direct drainage into the SVC and underscores the importance of considering operable congenital heart disease in adults presenting with unexplained cyanosis or murmurs, even in the absence of early life symptoms.