What is the most common cause of mitral stenosis?

• A. Rheumatic heart disease
• B. Calcific degeneration
• C. Infective endocarditis
• D. Ischemic heart disease

Answer: (A)

Rheumatic heart disease is the most common cause of mitral stenosis. After rheumatic fever, inflammatory changes thicken and scar the mitral leaflets and fuse their commissures, progressively narrowing the mitral valve orifice. This results in limited diastolic opening and a characteristic hemodynamic pattern. On ultrasound, you’d see thickened, often calcified leaflets with commissural fusion and diastolic doming of the anterior leaflet, producing a small mitral valve area and elevated transmitral gradients. Left atrial enlargement and signs of elevated pressures may also be present.

Other causes exist but are less common as the primary source of mitral stenosis. Calcific degeneration tends to occur in older patients and is less global in impact than rheumatic disease; infective endocarditis more often leads to vegetations and regurgitation; ischemic heart disease can cause functional stenosis but is not a typical primary cause.