Patent ductus arteriosus (PDA) is best described as what?

Patent ductus arteriosus (PDA) is best described as what?

• A. A passageway between the aorta and the pulmonary artery that remains open after birth
• B. A narrowing of the aorta
• C. A blockage of the pulmonary artery
• D. A coexisting defect causing cyanosis

Answer: (A)

PDA is a persistent connection between the aorta and the pulmonary artery that remains open after birth. In fetal life, the ductus arteriosus diverts blood away from the lungs; after birth, increased oxygen and changes in prostaglandins typically cause it to close. If it fails to close, blood flows from the higher-pressure aorta into the pulmonary artery, creating a left-to-right shunt and increasing pulmonary blood flow. This description directly names the anatomical route and the timing (open after birth), which is what defines PDA. Clinically, this can manifest as a continuous machinery-like murmur and may lead to respiratory symptoms or heart failure with larger openings. Other conditions describe narrowing of the aorta, blockage of the pulmonary artery, or cyanotic defects, which do not capture the sustained aorto-pulmonary connection that defines PDA.

PDA is a persistent connection between the aorta and the pulmonary artery that remains open after birth. In fetal life, the ductus arteriosus diverts blood away from the lungs; after birth, increased oxygen and changes in prostaglandins typically cause it to close. If it fails to close, blood flows from the higher-pressure aorta into the pulmonary artery, creating a left-to-right shunt and increasing pulmonary blood flow. This description directly names the anatomical route and the timing (open after birth), which is what defines PDA. Clinically, this can manifest as a continuous machinery-like murmur and may lead to respiratory symptoms or heart failure with larger openings. Other conditions describe narrowing of the aorta, blockage of the pulmonary artery, or cyanotic defects, which do not capture the sustained aorto-pulmonary connection that defines PDA.