Which description is pathognomonic for patent ductus arteriosus?

• A. Machinery-like murmur
• B. Harsh systolic murmur
• C. Vibratory murmur
• D. Venous hum

Answer: (A)

A continuous, machinery-like murmur heard best at the left infraclavicular area is the hallmark finding for patent ductus arteriosus. This murmur arises because blood flows continuously from the aorta into the pulmonary artery through the open ductus, so it spans both systole and diastole. Its persistence through all phases of the heartbeat, often with a wide pulse pressure and bounding pulses, makes it highly indicative of PDA in a newborn or child with this condition.

Harsh systolic murmurs point to other lesions such as obstructive or septal defects. A vibratory or Still’s murmur is an innocent, benign murmur common in children and typically does not extend into diastole. A venous hum is due to flow in the jugular veins and is soft and disappears with maneuvers like venous compression.