label: cor triatriatum sinister
label_lc: cor triatriatum sinister
description: "Cor triatriatum sinister (CTS) results when the left atrium is divided into two compartments by a membrane. The membrane can vary in size and shape and may have one or more openings. Severe cases of cor triatriatum sinister usually present in infancy and are often associated with other heart defects. In less severe cases, the diagnosis may not be made until later in life. The specific symptoms depend on the degree to which the membrane obstructs the flow of blood and whether or not there are additional heart defects. Symptoms may range from mild shortness of breath during exercise to signs of heart failure and lung congestion. Some people with CTS may not have symptoms. Treatment varies according to the severity of the symptoms. For symptomatic patients, surgery is generally consideredthe definitive course of therapy."