The ductus arteriosus is present in all fetuses allowing blood to bypass the non-functioning lungs. At birth or shortly after birth as the baby starts to breathe, the ductus arteriosus would normally close permanently. Failure to do so results in patent ductus arteriosus (PDA) which is an open channel allowing blood to flow from the aorta (blood vessel carrying blood from the heart to the rest of the body) to the pulmonary artery (blood vessel supplying the lung). If the PDA is large, the heart will be volume-loaded resulting in heart failure. The PDA also carries a risk of bacterial infection (infective endarteritis). PDA can be closed by inserting a device through the blood vessels in the groin (percutaneous transcatheter approach).