Unusual finding of cor triatriatum in a newborn with hypoplastic left heart syndrome.

Cor triatriatum is a rare anomaly in which the left atrium is partitioned into 2 distinct chambers with a variable degree of obstruction to left atrial inflow. This anomaly often occurs in isolation but can occur in combination with other cardiac lesions. The association of cor triatriatum with hypoplastic left heart syndrome has not been reported. We describe a newborn with hypoplastic left heart syndrome who also had the unusual finding of cor triatriatum sinistrum.