Echocardiographic assessment of mitral stenosis by the left atrial emptying index

Echocardiograms were performed in 35 patients prospectively with mitral stenosis to determine the usefulness of the left atrial emptying index (AEI) in estimating mitral valve orifice area (MVOA). 25 control patients without evidence of cardiac disease had an AEI of 0.91±0.01. In the mitral stenosis group, the mean AEI was 0.47±0.09, with Gorlin and Gorlin calculated MVOAs of 1.44±0.56. There was close correlation between the AEI and MVOA (r=0.93). The AEI did not correlate well with the left atrial size (r=0.10), or the EF slope of the mitral valve (r=0.20). The AEI was useful in separating patients with mitral stenosis into mild, moderate, and severe groups. 12 out of 12 patients with severe mitral stenosis (MVOA≤1.0 sq cm) had an AEI of ≤0.42. 10 out of 13 patients with moderate mitral stenosis (MVOA of 1.1-1.5 sq cm) had an AEI of 0.43 to 0.51. 8 out of 10 patients with mild mitral stenosis (MVOA≥1.6 sq cm) had an AEI of ≥0.52. The overall predictive value of the AEI in subclassifying the severity of mitral stenosis was 86%. In conclusion, the AEI appears to be a sensitive index in estimating MVOA in mitral stenosis.