5 Conclusion
AT/ET is a reliable and useful index for AS severity. However, AT/ET values obtained by the right parasternal approach is slightly greater than those obtained by apical approach, which should be called an attention to prevent incorrect diagnosis of AS severity. The right parasternal approach is useful to detect the highest peak transaortic velocity, however, AT/ET values obtained from the right parasternal approach were not always as same as those obtained from the apical approach.
Acknowledgement: We thank Ms Nakaya S, Mr Uechi T, and Ms Katamoto Y for their help in analysis of data variability.