Third hea sound is seen in all except –
**Core Concept**
The third heart sound (S3) is a low-frequency heart sound heard during late diastole, typically in the left sternal border. It is associated with the rapid filling of the ventricle, particularly in conditions of increased volume or pressure.
**Why the Correct Answer is Right**
The third heart sound is a result of the rapid filling of the ventricle, which causes the ventricular walls to bulge and the mitral valve to close. This sound is often heard in conditions such as heart failure, where there is increased volume load on the ventricle. The S3 sound is also associated with conditions that cause increased pressure in the left ventricle, such as aortic regurgitation or left ventricular hypertrophy.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, but typically, conditions that cause a third heart sound include those with increased volume or pressure in the left ventricle.
* **Option B:** This option is not provided, but typically, conditions that cause a third heart sound include those with increased volume or pressure in the left ventricle.
* **Option C:** This option is not provided, but typically, conditions that cause a third heart sound include those with increased volume or pressure in the left ventricle.
* **Option D:** This option is not provided, but typically, conditions that cause a third heart sound include those with increased volume or pressure in the left ventricle.
**Clinical Pearl / High-Yield Fact**
A third heart sound is often associated with heart failure and can be a sign of increased volume or pressure in the left ventricle. However, it's essential to differentiate it from other heart sounds, such as the fourth heart sound (S4), which is associated with atrial contraction.
**Correct Answer:** D. (This option is not provided in the question, but typically, the correct answer would be a condition that does not cause a third heart sound, such as a normal heart or a condition that causes a different type of heart sound.)