<unk><unk>  is a blood vessel connecting main pulmonary artery to proximal descending aorta
Shunts blood from right ventricle to bypass fetus's non-functioning lungs in utero
In<unk> ,<unk>  fails to close after birth
Second most common congenital heart disease
Approximately 1 in 1600 to 5000 live births in the US.
Shunts blood from right ventricle to bypass fetus's non-functioning lungs in utero<unk><unk>  shunts blood from the pulmonary artery to the aorta bypassing the lungs while in utero
Normally closes soon after birth via complex process
Regulated by oxygen tension and decreases in prostaglandin E2
Becomes ligamentum<unk> 
In<unk> ,<unk>  fails to close
Results in shunting of blood between aorta and pulmonary artery
Some oxygenated blood from high-pressure aorta shunts to lower pressure pulmonary artery
A large shunt can cause increased fluid return to lungs and increased lung pressure, leading to pulmonary hypertension
Some congenital heart defects, such as transposition of the great arteries, are incompatible with life 'without a<unk> ; may be necessary to allow oxygenated and deoxygenated blood to mix
In these cases prostaglandins are used to keep the<unk><unk>  open.
Regulated by oxygen tension and decreases in prostaglandin E2
Becomes ligamentum<unk> 
Results in shunting of blood between aorta and pulmonary artery
Some oxygenated blood from high-pressure aorta shunts to lower pressure pulmonary artery
A large shunt can cause increased fluid return to lungs and increased lung pressure, leading to pulmonary hypertension
In these cases prostaglandins are used to keep the<unk><unk>  open.
Patent ductus arteriosus
Acute pericarditis
Ebstein anomaly
Aortopulmonary Septal Defect
Tricuspid atresia
Coarctation of the Aorta
Atrial septal defect
Coronary artery fistula