Total Anomalous Pulmonary Venous Connections.

Total anomalous pulmonary venous connection is a rare congenital heart defect in which pulmonary veins drain into the systemic venous system rather than the left atrium, requiring an atrial communication for survival. Clinical presentation varies from severe neonatal cyanosis to milder symptoms later in infancy, with prognosis determined largely by pulmonary venous obstruction. Prenatal diagnosis is difficult but aided by targeted echocardiographic markers. Postnatal echocardiography is the diagnostic cornerstone, and individual vein size predicts outcomes. Surgical repair is the only definitive therapy; emergent surgery is indicated for obstruction, while stable non-obstructed cases undergo early planned repair. Modern techniques including primary sutureless repair have reduced postoperative pulmonary venous obstruction and improved survival.