A 42-year-old woman has noted progressive exercise intolerance and fatigability. Examination discloses an opening snap in the mitral area suggestive of mitral stenosis. The following is/are true:

c. Mural thrombi and thromboembolism are directly related to the presence of atrial fibrillation

Normal adults have a 4–6 cm2 mitral orifice and reduction to 2 cm2 is mild stenosis while reduction to 1 cm2 is considered critical mitral stenosis. Even with a fixed orifice, the onset of atrial fibrillation reduces cardiac output by 20%. Mural thrombi and thromboembolism are directly related to the presence of atrial fibrillation. Mitral stenosis spares ventricular function, and the loss of cardiac output is from decreased preload.