Qualitative and quantitative evaluation of supravalvar aortic stenosis by cross-sectional echocardiography. A report of 80 patients.

Cross-sectional and concurrent M-mode echocardiograms of the left ventricular outflow tract and the ascending aorta were performed in 80 patients with supravalvar aortic stenosis (SVAS) selected from a total of 178 patients in whom the diagnosis had been established earlier by cardiac catheterization and angiocardiography. Visualization of the area of obstruction was possible in 77 patients using the cross-sectional system. In 34 cases recatheterization and angiocardiography of the left heart were carried out. To quantitate the severity of obstruction we used the pressure difference across the stenosis and the ratio of the cross-sectional areas at the level of the aortic annulus and of maximal supravalve stenosis. These cross-sectional areas were estimated from values for aortic diameter derived from scans in the long axis of the aorta, assuming the cross-sections to be circular. There was a good correlation between the ratios calculated from the echocardiogram and those calculated from the angiocardiogram (r = 0.894, n = 34, 0.747 less than p greater than 0.938). There was also a good correlation between the ratio of the surface areas calculated from the echocardiogram and the corresponding measured pressure differences (r = 0.932, n = .36, 0.878 less than p greater than 0.973). This study shows that cross-sectional echocardiography may be useful for estimating the severity of obstruction in SVAS.