What type of heart murmur is characterized as crescendo/decrescendo?

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

Answer: (B)

The type of heart murmur characterized as crescendo/decrescendo is typically associated with aortic stenosis. This pattern refers to the intensity of the murmur increasing (crescendo) and then decreasing (decrescendo) over the course of the cardiac cycle.

In the case of aortic stenosis, as the left ventricle contracts to pump blood through a narrowed aortic valve, the flow of blood increases initially, leading to a crescendo effect as the pressure builds up. As the contraction progresses and the blood flow begins to taper off, the intensity of the murmur decreases, creating the decrescendo part of the sound. This murmur is most commonly heard during systole, specifically during the ejection phase of the cardiac cycle.

Other types of murmurs may have different characteristics. For example, aortic regurgitation produces a holosystolic or diastolic murmur rather than the crescendo/decrescendo pattern, and issues like mitral stenosis create a diastolic murmur. Tricuspid regurgitation is also more consistent rather than having a crescendo/decrescendo quality. Therefore, understanding the mechanics of aortic stenosis provides clarity on why it’s identified with this specific murmur pattern.