In rheumatic MS, the left atrial enlargement is typically disproportionate to the degree of stenosis.

In rheumatic MS, the left atrial enlargement is typically disproportionate to the degree of stenosis.

• A. Disproportionately Enlarged
• B. Proportionately Enlarged
• C. Not Enlarged
• D. Decreased

Answer: (A)

In chronic rheumatic mitral stenosis, the left atrium enlarges because elevated pressures and reduced compliance from the narrowed mitral valve push more blood backward into the atrium over time. This remodeling happens gradually, so the atrium can become quite large even when the valve narrowing isn’t extremely severe. That means the left atrial size often increases more than would be expected for the measured degree of stenosis, i.e., it is disproportionately enlarged. This pattern helps explain why patients with rheumatic MS may have marked atrial dilation and are at higher risk for atrial fibrillation and thromboembolism.

In chronic rheumatic mitral stenosis, the left atrium enlarges because elevated pressures and reduced compliance from the narrowed mitral valve push more blood backward into the atrium over time. This remodeling happens gradually, so the atrium can become quite large even when the valve narrowing isn’t extremely severe. That means the left atrial size often increases more than would be expected for the measured degree of stenosis, i.e., it is disproportionately enlarged. This pattern helps explain why patients with rheumatic MS may have marked atrial dilation and are at higher risk for atrial fibrillation and thromboembolism.