Scimitar syndrome is a rare congenital heart defect. Babies with scimitar syndrome are born with an underdeveloped right lung and pulmonary artery. They often need surgery to repair their heart. Many adults live healthy lives with scimitar syndrome. If they experience severe shortness of breath or repeat lung infections, they may need surgery.
Scimitar syndrome is a congenital (present at birth) heart defect. It’s a type of partial anomalous pulmonary venous return (PAPVR).
In scimitar syndrome, people have:
In about 1 in 3 people with scimitar syndrome, their right pulmonary vein is shaped like a scimitar, a curved Middle Eastern sword. Healthcare providers can see this shape on imaging.
A healthy heart takes in blood from your body and pumps it to your lungs. In your lungs, blood collects oxygen to carry back to your heart and the rest of your body.
A network of blood vessels called the circulatory system carries blood throughout your body. Blood circulates through two types of blood vessels:
Your pulmonary arteries and veins carry blood in and out of your lungs. The process has a few steps:
In scimitar syndrome, one or more of your pulmonary veins carries blood into the right side of your heart instead of the left side.
Sometimes, your right lung may also receive blood from your aorta instead of your pulmonary arteries. Your aorta is supposed to carry blood to the rest of your body.
Scimitar syndrome is rare. Only about 1 to 3 out of every 100,000 babies are born with the condition. It’s twice as common in females as in males.
Often, experts don’t know exactly what causes scimitar syndrome. Some factors can increase the risks that your baby will have a congenital heart defect. These risks include:
Sometimes, babies show scimitar syndrome symptoms immediately after birth. These symptoms include:
Other times, babies may grow into adulthood without showing any symptoms. Most adults with scimitar syndrome remain asymptomatic (show no symptoms). Adults who do have symptoms commonly experience:
Healthcare providers may use several tests to identify scimitar syndrome. These imaging tests tell providers about the size of your right lung and right pulmonary artery:
Your provider may also do cardiac catheterization, where they inject dye to look at your blood vessels and measure the pressures in your lungs and your body.
Healthcare providers treat scimitar syndrome with surgery. If a provider spots the condition in a baby, they usually operate within the first two months of life. Adults who have scimitar syndrome only need surgery if they have severe symptoms like repeat lung infections.
During surgery, a cardiac surgeon (heart doctor who does surgery) may:
There's no way to prevent having a child with scimitar syndrome. You can increase your chances of having a healthy baby by:
People who have surgery for scimitar syndrome typically have excellent long-term outcomes. Most people experience no further symptoms of scimitar syndrome after surgery. Some people, especially babies and young children, may develop some narrowing of the rerouted pulmonary vein, which could require additional treatment.
Some adults with scimitar syndrome experience no symptoms. However, many adults who have scimitar syndrome have other heart conditions that require treatment. These conditions may affect their quality of life. Adults may eventually need surgery if they begin showing symptoms of scimitar syndrome like severe shortness of breath or lung infections. Adults also may require special studies to determine whether they have elevated lung artery pressures.
Many people with scimitar syndrome have other cardiovascular problems. Some are born with multiple heart conditions. Or scimitar syndrome may lead to other complications.
People with other heart conditions may have:
You may want to ask your healthcare provider:
A note from Cleveland Clinic
Scimitar syndrome is a rare congenital heart defect. It affects the right lung and pulmonary arteries. Some babies may show no symptoms of the condition. Others may need surgery in their first two months of life. Babies that need early surgery may need additional surgery to address the narrowing of the rerouted veins. Some adults who have scimitar syndrome may live healthy lives without needing surgery. Most adults who have surgery for scimitar syndrome have excellent outcomes with typical life expectancy.
Last reviewed by a Cleveland Clinic medical professional on 04/11/2022.
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