Serendipitous diagnosis of cor triatriatum sinister in a child with Kawasaki disease.

Cor triatriatum is a rare congenital anomaly which has wide-ranging severity depending on the structure of the additional intra-atrial septum. We report the case of a boy who was incidentally diagnosed with cor triatriatum by echocardiography during diagnosis and treatment of Kawasaki disease. He has had no definite life-threatening symptoms except recurring respiratory infections. Serial follow-up of such patients is mandatory to check for the potential risks related to the anomalous inter-atrial structure. <Learning objective: Cor triatriatum is a rare congenital heart disease. We report a child who was incidentally diagnosed with cor triatriatum during diagnosis and treatment of Kawasaki disease. This child's cor triatriatum was not related to Kawasaki disease. However, we were fortunate to discover the co-occurrence of cor triatriatum, while undertaking echocardiography for Kawasaki disease. We should be aware of the possible missed diagnosis of some congenital heart disease.>.