Most common cause of mitral valve disease: March 2013
**Core Concept**
Mitral valve disease refers to a group of conditions affecting the mitral valve, which is a crucial structure responsible for ensuring blood flow between the left atrium and left ventricle. The most common cause of mitral valve disease involves degenerative changes leading to mitral regurgitation.
**Why the Correct Answer is Right**
The correct answer is rheumatic heart disease, which is the leading cause of mitral valve disease worldwide. Rheumatic heart disease results from an autoimmune response triggered by group A beta-hemolytic streptococcal infection, leading to inflammation and scarring of the valve. This process often causes the mitral valve to become stenotic or regurgitant.
**Why Each Wrong Option is Incorrect**
**Option A:** The correct answer is not mitral valve prolapse, although it is a significant cause of mitral regurgitation. However, it is less common than rheumatic heart disease.
**Option B:** The correct answer is not endocarditis, which can also cause mitral valve disease, but it is a relatively rare condition compared to rheumatic heart disease.
**Option C:** The correct answer is not mitral annular calcification, which can cause mitral stenosis, but it is a less common cause of mitral valve disease compared to rheumatic heart disease.
**Clinical Pearl / High-Yield Fact**
Rheumatic heart disease is a significant public health concern in developing countries, where it remains a leading cause of morbidity and mortality due to heart disease.
**Correct Answer: B. Endocarditis.**