Which heart sound is described as "crescendo-decrescendo"?

The heart sound described as "crescendo-decrescendo" is indicative of aortic stenosis. This characteristic pattern refers to how the intensity of the sound increases to a peak (crescendo) and then decreases after that peak (decrescendo) during systole.

In aortic stenosis, there's a narrowing of the aortic valve which creates turbulence as blood flows through during ventricular contraction. This results in a unique sound that typically can be best heard between the second intercostal space and the right sternal border. The crescendo-decrescendo pattern is a hallmark of the type of murmur associated with this condition, making it essential for healthcare providers to recognize it during auscultation.

Other heart conditions associated with regurgitation, like mitral and tricuspid regurgitation, do not typically produce this specific sound pattern, resulting in different murmur characteristics, often described as holosystolic or pansystolic, rather than crescendo-decrescendo. Aortic regurgitation, on the other hand, typically features a diastolic murmur and does not present with the same pattern either. Thus, understanding the distinct features of heart sounds helps in diagnosing and managing heart conditions effectively.