Which congenital lesion is classically associated with a continuous murmur best heard at the left infraclavicular area?

• A. ASD
• B. VSD
• C. Coarctation
• D. PDA

Answer: (D)

A persistent connection between the aorta and the pulmonary artery after birth, patent ductus arteriosus, produces a continuous “machinery” murmur that spans both systole and diastole. The ongoing flow from the high-pressure aorta into the lower-pressure pulmonary artery throughout the cardiac cycle creates this continuous sound, which is best heard at the left infraclavicular area where the ductus arteriosus is located. Other congenital lesions have different murmur patterns: for example, an atrial septal defect typically shows a fixed split S2 with a systolic ejection murmur, a ventricular septal defect causes a holosystolic murmur at the left lower sternal border, and coarctation often presents with a systolic murmur and differential blood pressures rather than a continuous murmur at that location.