In rheumatic heart disease, which valve is most commonly affected?

In rheumatic heart disease, which valve is most commonly affected?

• A. Aortic valve
• B. Mitral valve
• C. Tricuspid valve
• D. Pulmonary valve

Answer: (B)

The key idea is that rheumatic heart disease most often targets the mitral valve. After a streptococcal throat infection, an autoimmune reaction damages heart valves, but the mitral valve is the one most commonly involved because left-sided valves bear higher pressures and are more exposed to the inflammatory process. Over time this leads to chronic valvular changes, especially commissural fusion and thickening of the leaflets with shortening of the chordae, producing mitral stenosis—often described as a fish-mouth or buttonhole appearance. The aortic valve is the next most commonly affected, while the tricuspid and pulmonary valves are less frequently involved in classic rheumatic disease. This pattern explains why mitral stenosis is a hallmark finding in chronic rheumatic heart disease.

The key idea is that rheumatic heart disease most often targets the mitral valve. After a streptococcal throat infection, an autoimmune reaction damages heart valves, but the mitral valve is the one most commonly involved because left-sided valves bear higher pressures and are more exposed to the inflammatory process. Over time this leads to chronic valvular changes, especially commissural fusion and thickening of the leaflets with shortening of the chordae, producing mitral stenosis—often described as a fish-mouth or buttonhole appearance. The aortic valve is the next most commonly affected, while the tricuspid and pulmonary valves are less frequently involved in classic rheumatic disease. This pattern explains why mitral stenosis is a hallmark finding in chronic rheumatic heart disease.