RESUMEN
BACKGROUND: While it is the most common thoracic venous anomaly, a persistent left vena cava superior may present in atypical variations, which are important to consider during clinical management. CASE PRESENTATION: Here we report a 35-year-old Caucasian female patient with drainage into the left atrial appendage who presented with shortness of breath accompanied by mild hypoxemia. Venous contrast filling in the context of pulmonary scintigraphy suspected an additional superior caval vein connected to the left atrial appendage. Diagnosis was confirmed by transesophageal echocardiography. Cardiac catheterization revealed a minor right-to-left shunt. The symptoms could be allocated to a bronchial asthma and treated according to guidelines. Cerebral lesions detected in the patient were due to a coincident multiple sclerosis rather than cerebral embolisms. Thus, the venous anomaly was classified as an incidental finding currently requiring no treatment. CONCLUSIONS: To the best of our knowledge, this is the first report of a persistent left vena cava superior draining into the left atrial appendage.