USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

What cardiac condition presents with pulsus parvus et tardus and systolic ejection murmur?

1. Coarctation of the aorta

2. Patent ductus arteriosus

3. Aortic stenosis

4. Mitral stenosis

The correct answer is: Aortic stenosis

Pulsus parvus et tardus is a clinical finding characterized by a weak and delayed pulse, indicating diminished stroke volume and prolonged ejection time. This is commonly associated with aortic stenosis, a condition where the aortic valve narrows, leading to an obstruction to outflow from the left ventricle during systole. In aortic stenosis, the heart must work harder to eject blood through the narrowed valve, resulting in a decreased stroke volume. This reduced stroke volume translates to a weak pulse—pulsus parvus—while the delay in reaching peak pulse pressure accounts for the tardus aspect. The systolic ejection murmur heard in aortic stenosis is typically a harsh, crescendo-decrescendo sound best heard at the second right intercostal space and often radiates to the carotids. This murmur occurs due to turbulence as blood flows through the narrowed valve during systole. The other conditions listed do not commonly present with both pulsus parvus et tardus and a systolic ejection murmur. For instance, coarctation of the aorta may present with differential blood pressures in the arms and legs but not specifically with the signs directly indicative of aortic stenosis. Patent ductus