A comparison of echocardiographic techniques in determination of arterial elasticity in the pediatric population

Background: Many methods are used to measure arterial elasticity in children using echocardiography. There is no data to support the equivalence of the different techniques. The goal of this study was to evaluate the reproducibility of several techniques used to measure arterial elasticity using echocardiography. Methods: Aortic distension in two different sites (arterial distension) through the cardiac cycle was measured by (four) two-dimensional (2D) and M-mode echocardiographic techniques in 20 children without significant structural heart disease. These measurements combined with noninvasive blood pressure measurements were used to calculate arterial elastic indices. Arterial elasticity was expressed in terms of distensibility and stiffness. Data were collected by two sonographers and interpreted by two reviewers. Paired Student's t-test and Pitman's test for equality of variance for correlated observations were used to detect differences between different sonographers, different reviewers, and different techniques. Results: No significant difference in the measured elasticity between sonographers or reviewers was observed. There was a somewhat increased variance in two of the four techniques evaluated. There was no significant difference in elasticity measured using different techniques to evaluate the same arterial site, although a significantly decreased elasticity was noted from measurements taken in the proximal ascending aorta as compared with the distal ascending aorta. Conclusions: Many echocardiographic techniques produce reproducible measurements of arterial elasticity. There may be intrinsic differences in arterial elasticity between different segments of the ascending aorta, which have not been previously described in children with normal cardiac anatomy. Comparisons of data from separate studies must take these differences into account.