The accentuated first sound, results from fibrotic changes in the mitral valve and chordae tendineae and possibly form a higher closing pressure. The opening snap of mitral stenosis occurs between 0.06 and 0.10 second after the aortic second sound and the more severe the mitral stenosis, the closer it occurs to the aortic sound. The earliest murmur in mitral stenosis is usually a short rumbling middiastolic murmur which is produced as blood flows through the narrowed mitral valve during the phase of rapid filling of the ventricle. The murmur is best heard at the apex in the left lateral position with the bell applied lightly to the chest wall. If the bell is applied too firmly and the murmur is not very loud, the murmur will not be heard.
Auscultation remains the principle method of detecting mitral stenosis.
In pure mitral stenosis, the diagnosis is not difficult and is made by auscultation. When there is multiple valve disease, the severity of the mitral stenosis may be more difficult to determine. The echocardiogram provides a good estimation of the degree of obstruction. Cardiac catheterization may be necessary in some complex cases. In any patient with pulmonary hypertension, mitral stenosis should be carefully considered and either excluded or established.