Evaluation of the Severity of Aortic Valve Stenosis by Ejection Fraction-Velocity Ratio: Function-Corrected Index in Children

Background- In the evaluation of the severity of aortic valve stenosis with echocardiography or catheterization, ventricular function seems to have an impact on the estimation of preferential non-invasive procedure of echocardiography. Methods- Fifty-seven patients, who had valvar aortic stenosis without any left heart lesion or ventricular septal defect, were referred to our department for an examination. Mean pressure gradient and indexed aortic valve area (to body surface area) based on the continuity equation, and ejection fraction ratio to peak and mean velocities and pressure gradients across the aortic valve ("function-corrected" indices) were calculated by echocardiography and were compared with one another. The patients were subsequently classified into four groups based on their ejection fraction, and the calculations were done in each group again. Results- In the two groups of ejection fraction less than 65% and more than 85%, the inadequacy in the number of cases precluded a judgment. In the group of ejection fraction between 65% and 75%, there were good correlations between mean gradients and the ratios and good correlation between indexed aortic valve area and the ratios to velocities, but not pressure gradients. In the group of ejection fraction between 75% and 85%, there were good correlations between all of those variables. Conclusion- In the intermediate spectra of the ejection fraction and consequently ventricular function, there were no differences between "function-corrected" indices and previous estimations of mean gradients and aortic valve areas. There is, however, need for further studies with larger numbers of patients to evaluate the correlation of the "function-corrected" indices with mean gradients and aortic valve areas in the upper and lower limits of ejection fraction.