In bacterial endocarditis, which valve is most commonly affected in patients with rheumatic fever?

In the context of rheumatic fever, the mitral valve is the most commonly affected valve in cases of bacterial endocarditis. Rheumatic fever is a complication of untreated streptococcal throat infections, which can lead to rheumatic heart disease. This condition primarily impacts the heart valves due to autoimmune reactions following an infection. The mitral valve is particularly susceptible because of its position and the hemodynamic stresses it experiences.

In rheumatic heart disease, the mitral valve's leaflets become inflamed, thickened, and may develop scarring, leading to issues such as regurgitation or stenosis. When bacterial endocarditis occurs in a patient with a history of rheumatic fever, the mitral valve is often the site of infection due to these pre-existing structural abnormalities, making it the valve most typically involved in these cases.

This helps reinforce the understanding that the mitral valve has a unique vulnerability due to its involvement in rheumatic heart disease, distinguishing it from the aortic, tricuspid, or pulmonic valves, which are less commonly associated with this particular complication.