Adult cor-triatriatum sinistrum-a sinistral lesion with varied presentations: a case series.

Background: Cor-triatriatum sinistrum (CTS) is a rare congenital heart disease, characterized by a membrane dividing the left atrium into two chambers. Echocardiography is the primary imaging modality. However, computed tomography and magnetic resonance imaging both play important roles in delineating the anatomy of the condition and also determining the associated anomalies. Although thought to be a disease of childhood, CTS can also present in adulthood with varied clinical manifestations like dyspnea, palpitations, and syncopal attacks. In CTS, the left atrial membrane causes pulmonary venous obstruction and eventual pulmonary arterial hypertension. It is usually associated with membrane fenestrations, which allow some antegrade flow. If not, there are relief valves, such as the ostium secundum atrial septal defect (OS-ASD) and/or the levo-atrial-cardinal vein. Case summary: We present three patients with CTS. The first patient is of Type I CTS-presenting with CTS and an OS-ASD, which is acting as a relief valve. The second patient is of Type II CTS with associated levo-atrio-cardinal vein and venovenous shunting. The third patient presented with CTS with partial anomalous pulmonary venous connection (PAPVC)-suggestive of Type III CTS. All the cases were managed surgically with good outcomes. Discussion: CTS, though thought to be a disease of childhood, may present in adults with varied clinical presentations. Imaging plays a crucial role in the diagnosis and delineation of associated anomalies. Management is usually surgical with a good clinical outcome.