Learn about a USMLE® Step 1 question of the day related to systolic ejection murmur, specifically focusing on aortic stenosis. Discover the characteristics of this murmur and how to recognize it during auscultation.
A 66-year-old man presents to a cardiologist for evaluation of a new heart murmur discovered at a routine health screening evaluation. The physician reads the report from this evaluation, which states that the patient was found to have a “crescendo-decrescendo systolic ejection murmur.” Auscultation at which of the following anatomic locations is most appropriate for reproducing this patient’s characteristic murmur?

Scroll down for the correct answer!
The correct answer to today’s USMLE® Step 1 Question is…
A. A
Before we get to the Main Explanation, let’s look at the incorrect answer explanations. Skip to the bottom if you want to see the correct answer right away!
Incorrect answer explanations
B. B
Incorrect: Choice B corresponds to the pulmonic area. This patient’s classic “crescendo-decrescendo systolic ejection murmur” is most likely from aortic stenosis, which is best heard over the aortic area (area A).
C. C
Incorrect: Choice C corresponds to the tricuspid area.This patient’s classic “crescendo-decrescendo systolic ejection murmur” is most likely from aortic stenosis, which is best heard over the aortic area (area A).
D. D
Incorrect: Choice D corresponds to the mitral area. This patient’s classic “crescendo-decrescendo systolic ejection murmur” is most likely from aortic stenosis, which is best heard over the aortic area (area A).
E. E
Incorrect: Choice E does not correspond to a defined auscultatory location. This patient’s classic “crescendo-decrescendo systolic ejection murmur” is most likely from aortic stenosis, which is best heard over the aortic area (area A).
Main Explanation

The characteristic crescendo-decresendo systolic ejection murmur described in the question stem refers to aortic stenosis, which is best appreciated over the second intercostal space along the right sternum. Several anatomic areas of the chest wall serve as landmarks for auscultation of different valves of the heart:
- Aortic area: Right second intercostal space, parasternal. Aortic valve murmurs are heard best here, including aortic stenosis (systolic) and aortic regurgitation (diastolic).
- Pulmonic area: Left second intercostal space, parasternal. Pulmonic murmurs heard best here, like the systolic ejection murmur of pulmonic stenosis. Physiologic flow murmurs are also best heard here.
- Tricuspid area: Left fourth intercostal space, parasternal. Diastolic murmurs associated with tricuspid stenosis or atrial septal defects can be heard here, as well as holosystolic murmurs from tricuspid regurgitation and ventricular septal defects.
Mitral area: Left fifth intercostal space, mid-clavicular. One can hear the systolic murmurs from mitral regurgitation or mitral valve prolapse here, in addition to the diastolic mitral stenosis murmur.
Major Takeaway
Anatomic areas of the chest wall correspond to different valves of the heart for auscultation. Using this knowledge, one can elicit murmurs associated with specific cardiac valvular pathology.
References
Hockberger, Robert, Ron Walls, and John Marx. Rosen’s Emergency Medicine: Concepts and Clinical Practice. Saunders, 2012. Print.
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The United States Medical Licensing Examination (USMLE®) is a joint program of the Federation of State Medical Boards (FSMB®) and National Board of Medical Examiners (NBME®). Osmosis is not affiliated with NBME nor FSMB.
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