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). Twnety-five 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. Twelve out of 12 patients with severe mitral stenosis (MVOA less than or equal to 1.0 sq cm) had an AEI of less than or equal to 0.42. Ten 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. Eight out of ten patients with mild mitral stenosis (MVOA greater than or equal to 1.6 sq cm) had an AEI of greater than or equal to 0.52. The overall predictive value of the AEI in subclassifying the severity of mitral stenosis was 86 percent. In conclusion, the AEI appears to be a sensitive index in estimating MVOA in mitral stenosis.