The clinical presentation of a preterm infant with a persistent patent ductus arteriosus (PDA) typically begins with which finding?

• A. Coarse Systolic Murmur Best Heard Along the Left Sternal Border
• B. Continuous ‘Machinery Like’ Murmur Heard Bilaterally in the Anterior Chest
• C. Short Mid-Systolic Murmur That Radiates to the Inter-Scapular Area
• D. No Murmur Audible

Answer: (A)

A continuous, machinery-like murmur heard over the precordium is the hallmark sign of a persistent patent ductus arteriosus in a preterm infant. This murmur reflects ongoing blood flow from the aorta to the pulmonary artery during both systole and diastole, due to the ductus remaining open. It is typically best heard along the left upper sternal border or left infraclavicular area, and may be accompanied by signs of increased pulmonary flow such as bounding pulses and wide pulse pressure. In some cases, especially in very small PDAs, the murmur can be soft or difficult to hear, but when present, the continuous character distinguishes PDA from purely systolic murmurs.