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 at birth as the baby starts breathing. But
if the vessel does not close, it is known as a patent (open)
ductus arteriosus (PDA). 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.
Some babies do not have symptoms from a patent ductus
arteriosus. But this abnormality often causes symptoms, such as
poor feeding and shortness of breath. An older child may develop
heart failure or an infection of the heart's inner lining
(infective endocarditis). How bad