Three-dimensional transthoracic echocardiography to evaluate cor triatriatum in the adult.

Cor triatriatum is a rare congenital condition in which the left atrium is partitioned into two chambers by a fibrous or fibromuscular septum. The diagnosis is often made early in childhood, but can rarely be discovered later in adulthood. This delay in diagnosis is likely because of the number and size of the fenestrations in the septum. Echocardiography is the modality most often used to diagnose cor triatriatum. Generally, transesophageal echocardiography (TEE) is superior to transthoracic imaging. Three-dimensional echocardiography, however, is a modality that offers additional information not offered by 2-dimensional echocardiography. Although 3-dimensional TEE has previously been described, we report what we believe to be the first case of 3-dimensional transthoracic echocardiography used to diagnose cor triatriatum. This modality offers an advantage over TEE, as it allows the septum to be viewed easily without the risks or inconvenience of TEE.