MC valve involved in Rheumatic fever –
**Core Concept**
Mitral valve involvement is a hallmark of rheumatic fever, a complication of untreated or inadequately treated group A beta-hemolytic streptococcal pharyngitis. The mitral valve is the most commonly affected valve in rheumatic heart disease.
**Why the Correct Answer is Right**
The mitral valve is susceptible to rheumatic inflammation due to its unique anatomy, with the mitral valve leaflets being richly innervated and having a high concentration of immune cells. The valve's fibrosa and ventricularis surfaces are particularly prone to inflammatory damage, leading to fibrosis and calcification. This process can result in valvular stenosis or regurgitation, depending on the extent of the damage.
**Why Each Wrong Option is Incorrect**
**Option A:** The aortic valve is less commonly affected than the mitral valve in rheumatic fever due to its lower innervation density and immune cell concentration.
**Option B:** The tricuspid valve is rarely involved in rheumatic fever, as it is less susceptible to the inflammatory process.
**Option C:** The pulmonary valve is not typically affected in rheumatic fever, as it is not exposed to the same level of immune-mediated inflammation as the other valves.
**Clinical Pearl / High-Yield Fact**
In patients with a history of rheumatic fever, the mitral valve is the most likely valve to be affected, and valvular involvement is a key component of the Jones criteria for diagnosing acute rheumatic fever.
**Correct Answer: . Mitral valve**