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Patent Ductus Arteriosus — EECC MCQ

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EasyCongenital Heart Disease (Adult)Patent Ductus ArteriosusEECC

A 5-day-old neonate is found to have a continuous machinery murmur at the left infraclavicular area. Echocardiography confirms a large patent ductus arteriosus (PDA) with left-to-right shunt causing LA and LV dilatation. What is the mechanism of the continuous murmur?

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Correct answer: E — Continuous left-to-right flow through the ductus from the aorta to the pulmonary artery throughout both systole and diastole due to the persistent aortic-to-PA pressure gradient

A PDA produces a continuous (Gibson) murmur because the pressure in the aorta exceeds that in the pulmonary artery throughout both systole and diastole, creating continuous left-to-right flow. The murmur is classically described as a 'machinery murmur' heard best at the left infraclavicular area. In neonates, a large PDA with significant shunt requires closure to prevent volume overload of the left heart and eventual pulmonary hypertension. In preterm infants, pharmacological closure with ibuprofen or indomethacin (COX inhibitors) may be attempted first. In term infants and older children/adults, percutaneous device closure is standard. The 2020 ESC ACHD Guidelines recommend closure of haemodynamically significant PDAs regardless of age.

Reference: ESC (2020): Guidelines for the Management of Adult Congenital Heart Disease