A continuous machine-like murmur heard best at the left upper sternal border suggests which congenital condition?

A continuous machine-like murmur heard best at the left upper sternal border suggests which congenital condition?

• A. Patent Ductus Arteriosus
• B. Atrial Septal Defect
• C. Ventricular Septal Defect
• D. Coarctation of the Aorta

Answer: (A)

The key idea is recognizing a continuous, machinery-like murmur as characteristic of a patent ductus arteriosus. When the ductus arteriosus fails to close after birth, blood shunts from the high-pressure aorta to the lower-pressure pulmonary artery throughout both systole and diastole. That persistent flow creates a continuous murmur that is best heard along the left upper sternal border. Clinically, PDA often presents with a continuous murmur and may be accompanied by a wide pulse pressure and bounding pulses due to diastolic runoff. In contrast, other congenital defects produce different auscultatory patterns: an atrial septal defect typically yields a systolic ejection murmur with a fixed split S2; a ventricular septal defect presents a holosystolic murmur at the left lower sternal border; coarctation of the aorta is not described by a continuous murmur and more often involves diminished femoral pulses or differential blood pressure.

The key idea is recognizing a continuous, machinery-like murmur as characteristic of a patent ductus arteriosus. When the ductus arteriosus fails to close after birth, blood shunts from the high-pressure aorta to the lower-pressure pulmonary artery throughout both systole and diastole. That persistent flow creates a continuous murmur that is best heard along the left upper sternal border. Clinically, PDA often presents with a continuous murmur and may be accompanied by a wide pulse pressure and bounding pulses due to diastolic runoff.

In contrast, other congenital defects produce different auscultatory patterns: an atrial septal defect typically yields a systolic ejection murmur with a fixed split S2; a ventricular septal defect presents a holosystolic murmur at the left lower sternal border; coarctation of the aorta is not described by a continuous murmur and more often involves diminished femoral pulses or differential blood pressure.