Cross-sectional echocardiographic assessment of the severity of aortic stenosis in children.

Real-time, cross-sectional echocardiographic studies of the aortic valve were performed in 28 children with congenital valvular aortic stenosis and in 22 normal subjects. The presence of a stenotic valve was indicated by increase in echo production, abnormal motion pattern, and abnormal systolic position of the valve leaflets. Comparison of the maximum aortic cusp separation (MACS) to calculated aortic valve area yielded an r of 0.91. MACS was then expressed as a percentage of aortic root diameter (AOD) to correct for patient size. In normals MACS averaged 72.7% (range 63-92%) of AOD. With mile aortic stenosis MACS averaged 53.1% of AOD (range 42-62%) (P less than 0.001 vs normal). With moderate and severe aortic stenosis MACS averaged 29.9% of AOD (range 20-35%) (P less than 0.001 vs mild AS). Comparing the ratio MACS/AOD to peak systolic gradient yielded an r of 0.88. Further comparing this ratio to calculated aortic valve area yielded an r of 0.80. Cross-sectional echocardiography can detect the presence of aortic stenosis in children and, by comparing the ratio MACS/AOD, can provide information concerning the severity of the stenotic lesion.