A Silent Start: Unmasking a TAPVC in Adulthood

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BSTRACT

Total anomalous pulmonary venous connection (TAPVC) is a rare congenital cardiac malformation in which all pulmonary veins fail to connect to the left atrium and instead drain anomalously into the systemic venous circulation. This results in the admixture of oxygenated and deoxygenated blood within the right atrium, leading to systemic desaturation, right heart volume overload, and, in many cases, pulmonary hypertension. The clinical presentation is sometimes nonspecific—particularly in unobstructed forms—and may include mild cyanosis, respiratory distress, or fatigue. These subtle findings frequently contribute to delayed diagnosis, underscoring the need for high clinical suspicion in patients, especially infants and children, with unexplained cyanosis or right heart enlargement. The hemodynamic burden of TAPVC is largely influenced by the presence or absence of venous obstruction and the degree of pulmonary vascular resistance. Without surgical intervention, the prognosis is poor, with less than 20% of affected infants surviving beyond the first year of life. ^[2-4] Although survival into adulthood is rare, it may occur in cases with unobstructed venous drainage, allowing for compensated but inefficient circulation. Increasing awareness of TAPVC’s heterogeneous presentations and improved imaging techniques have enhanced diagnostic accuracy. Here, we report a rare case of unobstructed intracardiac TAPVC in a 26-year-old man, successfully managed with definitive surgical repair, highlighting the potential for positive outcomes even in late-presenting cases.