Abstract
BACKGROUND: Cor triatriatum has been described as a heart with three atria in which the left atrium (cor triatriatum sinistrum) or right atrium (cor triatriatum dextrum) is divided into two compartments by a fold of tissue, a membrane, or a fibromuscular band. Double-chambered right ventricle, on the other hand, is identified by the presence of an anomalous muscle bundle dividing the right ventricle into two chambers. CASE PRESENTATION: Here, we describe the case of a child who had a combination of both of these rare entities, effectively creating a heart with six chambers. The child underwent a successful intracardiac repair. CONCLUSIONS: The association of CTS with DCRV forming a "6-chambered heart" is extremely rare. Awareness of its existence and accurate preoperative diagnosis has important implications in its surgical repair with all the components of this disease spectrum, further increasing the complexity of a successful surgical repair.