Determination of aortic valve are in valvular aortic stenosis by direct measurement using intracardiac echocardiography: comparison with the gorlin and continuity equations

Objectives. This study sought to 1) show that intracardiac echocardiography can allow direct measurement of the aortic valve area, and 2) compare the directly measured aortic valve are from intracardiac echocardiography with the calculated aortic valve are from the Gorlin and continuity equations. Background. Intracardiac echocardiography has been used in the descriptive evaluation of the aortic valve; however, direct measurement of the aortic valve are using this technique in clinical setting has not been documented. Despite their theoretical and practical limitations, the Gorlin and continuity equations remain the current standard methods for determining the aortic valve orifice area. Methods. Seventeen patients underwent intracardiac echocardiography for direct measurement of the aortic valve area, including four patients studied both before and after valvuloplasty, for total of 21 studies. Immediately after intracardiac echocardiography, hemodynamic dat were obtained from transthoracic echocardiography and cardiac catheterization. Results. Adequate intracardiac echocardiographic images were obtained in 17 (81%) of 21 studies. The average aortic valve are (mean ± SD) determined by intracardiac echocardiography for the 13 studies in the Gorlin analysis group was 0.59 ± 0.18 cm2 (range 0.37 to 1.01), and the average aortic valve are determined by the Gorlin equation was 0.62 ± 0.18 cm2 (range 0.31 to 0.88). The average aortic valve are determined by intracardiac echocardiography for the 17 studies in the continuity analysis group was 0.66 ± 0.23 cm2 (range 0.37 to 1.01), and that for the continuity equation was 0.62 ± 0.22 cm2 (range 0.34 to 1.06). There was significant correlation between the aortic valve are determined by intracardiac echocardiography and the aortic valve are calculated by the Gorlin (r = 0.78, p = 0.002) and continuity equations (r = 0.82, p < 0.0001). Conclusions. In the clinical setting, intracardiac echocardiography can directly measure the aortic valve are with an accuracy similar to the invasive and noninvasive methods currently used. This study demonstrates new, quantitative use for intracardiac echocardiographic imaging with many potential clinical applications.