Family Nurse Practitioner Exam

What is the most likely diagnosis for a medium-pitched harsh systolic murmur best heard at the right upper border of the sternum?

1. A) Mitral stenosis

2. B) Aortic stenosis

3. C) Pulmonic stenosis

4. D) Tricuspid regurgitation

The correct answer is: B) Aortic stenosis

The description of a medium-pitched harsh systolic murmur best heard at the right upper border of the sternum strongly suggests aortic stenosis. This condition typically produces a characteristic murmur that occurs during systole, resulting from the turbulent blood flow across a narrowed aortic valve. The location where the murmur is best heard, specifically at the right upper sternal border, is consistent with aortic stenosis, as this area corresponds to the anatomical position of the aortic valve. Additionally, the medium pitch and harsh quality of the murmur can be attributed to the increased flow velocity due to the stenosis. In contrast, other options describe different murmurs associated with other cardiovascular conditions. For example, mitral stenosis produces a diastolic murmur best heard at the apex, while pulmonic stenosis typically generates a murmur that is heard best in the left upper sternal border and may be described as a "crescendo-decrescendo" sound. Tricuspid regurgitation usually presents as a holosystolic murmur heard best along the left sternal border. Understanding the correlation between the characteristics of the murmur and the heart valve involved helps in accurately diagnosing conditions like aortic stenosis.