What is cor triatriatum?

Cor triatriatum is a rare congenital heart defect characterized by abnormal partitioning within the left atrium. In this condition, the left atrium is divided into two chambers by a fibrous band or membrane. This abnormal septation can impede normal blood flow from the pulmonary veins to the left ventricle. Consequently, this condition leads to various signs and symptoms, including respiratory distress and other issues related to reduced blood flow.

In this context, the choice indicating abnormal septation in the left atrium accurately describes the nature of cor triatriatum. Understanding this condition is important for identifying patients who may present with symptoms related to impaired circulation due to this structural heart anomaly. Other options, such as the presence of three atria or absence of atrial structures, do not accurately reflect the pathology of cor triatriatum, as the condition specifically involves a division within the left atrium rather than an increase in the number of atria or a complete absence of them.