Sinus venosus ASD.

A 32-year-old man presented at the cardiology department for a routine check-up. He had no symptoms, particularly no cardio logical symptoms. Clinical examination and ECG revealed no abnormalities. Transthoracic echocardiography showed a mild dilatation of the right heart. Further functional evaluation of the right heart was performed with MRI to evaluate the presence of a left to right shunt as a possible cause of right heart dilatation. We used the phase-contrast technique to measure the flow in the left ventricular outflow tract (Qs = 4,6 l/min) and right ventricular outflow tract (Qp = 13 l/min). The Qp/Qs ratio measured 2.88, indicating a severe left to right shunt. Anatomical work up included a cardiac CT. It showed a dilated right heart (Fig. A) with a large defect in the upper atrial septum (Fig. B) contiguous with the superior vena cava, which is a sinus venosus type of atrial septal defect (SVASD). There was also an anomalous drainage of the right upper lobe pulmonary vein in the superior vena cava (Fig. C).