Let's put the clues together and find the aetiology in this patient with dilated right heart!

A 39-year-old woman with intermittent palpitations, psoriasis, and a family history of sudden death presented with dilated right heart chambers and an enlarged coronary sinus. Despite a normal bubble study, further evaluation with transesophageal echocardiography revealed an abnormal pulmonary venous return: the left pulmonary veins drained into the coronary sinus. Cardiac computed tomography confirmed this finding, suggesting a partial abnormal pulmonary venous return as the underlying issue. Cardiac catheterization indicated increased pulmonary artery flow with normal pulmonary vascular resistance. The patient was referred for surgery. In this pathway involving the differential diagnosis of right heart dilatation, despite a confusing history and conflicting findings, echocardiographic clues led to the diagnosis.