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Diagnosis, management, and follow-up of systemic venous drainage via a single left superior caval vein into the left atrium

A 15-month-old boy presented with asymptomatic hypoxaemia due to right-to-left venous shunting via a left superior caval vein emptying into the left atrium, in absence of right superior caval vein. The diagnosis, suspected by contrast echocardiography, was confirmed by computed tomography and angiography. The child underwent surgical correction of the systemic anomalous return by tunnelling the left superior caval vein towards the right atrium. An asymptomatic narrowing inside the intra-atrial baffle developed 6 months later.