Scimitar syndrome is a congenital heart defect characterized by an unusual arrangement of the pulmonary veins. In patients with this condition, one or more of the pulmonary veins in the right lung drain to the side of the heart that normally collects deoxygenated blood from the body so it can be pushed to the lungs. This causes the heart to work harder than normal and can lead to an enlarged heart and other medical problems.
The severity of scimitar syndrome varies considerably. Some people have it and are completely unaware of it, or diagnose it, but a doctor determines that the effects are so mild that no action is necessary. In other cases, the defect causes health problems or puts the heart in danger, in which case surgery may be recommended to address the problem. This condition is also known as partial pulmonary venolobar syndrome.
In a patient with pulmonary venolobar syndrome, the veins have a distinctive appearance when viewed on X-ray, resembling the Middle Eastern weapon known as a scimitar, and explain the term "scimitar syndrome." The patient's pulmonary veins may drain completely or partially on the wrong side of the heart, and sometimes the heart is on the right side of the chest instead of the left. The affected lung and pulmonary veins tend to be smaller than normal, another finding that will be visible on x-ray.
This rare heart defect is usually diagnosed when someone appears to be experiencing heart problems and a doctor orders medical imaging to get an idea of what's going on inside the heart. Signs of heart problems can include irregular heartbeat, weakness, dizziness, shortness of breath, and chest pain. Using an x-ray, a doctor can identify the telltale "scimitar sign" that indicates the presence of this defect and determine its severity based on anatomical changes that can be seen in the chest.
Some hereditary factors seem to be involved with scimitar syndrome. In families with a history of this birth defect, children are more likely to be born with it. In other cases, it appears spontaneously, with no clear family history of the condition. It is important to note that no known family history is not the same as no family history. Someone in the family may have scimitar syndrome, but have such a mild case that it was never identified.