A very rare case: Cor polyatriatum, a variant of cor triatriatum.

Cor triatriatum sinister is a rare congenital heart anomaly. We present an elderly patient with cor polyatriatum, which is a variant of cor triatriatum. The patient was admitted to our hospital with symptoms of congestive heart failure. Echocardiographic evaluation revealed that the left atrium was divided into three spaces of the fibromuscular membrane, resembling a railway. Diagnosis was confirmed by cardiac magnetic resonance imaging. The patient did not accept surgical treatment and was followed medically.