A diastolic blowing murmur at the left sternal border in a patient with repaired coarctation most likely indicates which condition?

• A. Aortic regurgitation
• B. Aortic stenosis
• C. Mitral regurgitation
• D. Tricuspid regurgitation

Answer: (A)

The main concept is that a diastolic blowing murmur heard along the left sternal border points to aortic regurgitation. In aortic regurgitation, blood leaks backward from the aorta into the left ventricle during diastole, producing a high-pitched, blowing, decrescendo murmur best heard at the left sternal border, often with the patient leaning forward. In someone with repaired coarctation, there’s an increased likelihood of associated aortic valve or root involvement (such as bicuspid aortic valve or aortic dilation), which can lead to AR. Other conditions produce different murmur patterns: aortic stenosis is a systolic murmur, mitral regurgitation is typically holosystolic at the apex, and tricuspid regurgitation is holosystolic at the left lower sternal border, not a diastolic blowing murmur.