Patent ductus arteriosus

The ductus arteriosus is a blood vessel in a fetus that connects the pulmonary artery, which carries blood to the lungs, and the aorta, which carries blood to the body, so that blood flow bypasses the lungs. Normally, this blood vessel closes shortly after birth; when it does not, it is known as a patent (open) ductus arteriosus.

A patent ductus arteriosus allows some oxygen-rich blood to flow from the aorta back into the pulmonary artery and to the lungs instead of to the rest of the body. Because some of the blood intended for the body returns to the lungs, the left side of the heart has to pump harder to get enough blood to the body. This can enlarge and weaken the heart.

Although some babies do not experience symptoms from a patent ductus arteriosus, this abnormality often causes a variety of symptoms, such as poor feeding and shortness of breath. Eventually, if the patent ductus is not closed, a baby may develop an infection of the heart's inner lining (infective endocarditis) or heart failure. The severity of the symptoms and whether complications develop depend on how much blood flows through the ductus.

Treatment for a patent ductus arteriosus may include medication or surgery. Surgery usually is not attempted until a baby is at least 6 months of age, unless serious problems develop before that time.