Final answer:
Persistent PDA can have long-term effects such as respiratory infections and congestive heart failure. A PDA closure is indicated when there are significant symptoms or complications.
Step-by-step explanation:
**Persistent Patent Ductus Arteriosus (PDA)** is a condition where the ductus arteriosus, a blood vessel that connects the aorta and the pulmonary artery, remains open after birth. The sequelae or long-term effects of persistent PDA can include increased risk of respiratory infections, congestive heart failure, and development of pulmonary hypertension. A PDA closure is indicated when the PDA causes significant symptoms or complications, such as failure to thrive, recurrent respiratory infections, or heart failure.