Patent Ductus Arteriosus  (PDA) 

PDA is one of  the most common cardiac anomalies. It occurs twice as frequently in girls as in boys. 

In patent ductus Arteriosus there is a communication between the pulmonary artery and aorta. The ductus arteriosus is normally present in fetal life and connects the pulmonary artery to the aorta, thus blood reaches the aorta through this opening since the lungs are collapsed during fetal life. This ductus arteriosus normally closes after birth due to initiation of  pulmonary respiration. Persistence of ductus arteriosus after birth is called patent ductus arteriosus.