During auscultation of the heart, a harsh crescendo-decrescendo systolic ejection murmur is heard loudest at the right second intercostal space with radiation to the carotids. There is a delayed, weak carotid pulse (pulsus parvus et tardus). What is the underlying valvular pathology?

Answer and explanation

Correct answer: B. Aortic stenosis

  1. Step 1: Identify the murmur characteristics: a harsh crescendo-decrescendo systolic ejection murmur localized to the right upper sternal border (right 2nd intercostal space) radiating to both carotids is pathognomonic for left ventricular outflow tract obstruction at the aortic valve.
  2. Step 2: The delayed opening and fixed stenosis of the calcified aortic valve restricts stroke output, resulting in a delayed, diminished carotid arterial upstroke known as pulsus parvus et tardus.
Answer
Aortic stenosis.
Why not the others: Mitral regurgitation produces a holosystolic, blowing murmur loudest at the cardiac apex radiating to the axilla; Aortic regurgitation causes an early diastolic decrescendo blowing murmur with a bounding water-hammer pulse (Corrigan pulse); Hypertrophic cardiomyopathy produces a systolic murmur that increases with Valsalva and does not radiate to the carotids.

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