Background Reduced arterial compliance will be associated with rapid decrease in pressure gradient across left ventricular outflow tract (LVOT) and ascending aorta. We hypothesized that LVOT flow deceleration and its dynamic changes during exercise would be correlated with augmentation index (Ax) at rest and during exercise. Methods In 91 subjects (32 men, 58 yrs), the multistage (25W, 3 mins increments) supine bicycle exercise testing and simultaneous measurement of AIx with radial artery tonometry (SphygmoCor짰, AtCor Medical) were performed. The patients who had any structural heart diseases were excluded. The AIx were obtained at rest as well as immediately (<1 min) after peak exercise. The blood flow velocities through the LVOT were recorded using pulsed Doppler at rest and during exercise and measured parameters as defined in Figure.Results The ratio of deceleration to ejection time (DT/ET) at rest, 25W and 50W exercise were not correlated with resting AIx. However, these parameters showed significant correlations with Aix at immediately after peak exercise(r=0.314,p=0.003;r=0.221,p=0.040;r=0.261,p=0.017). These correlations were stronger in the ratio of deceleration to acceleration time (DT/AT) (Figure 1B).Conclusions The LVOT Doppler pattern was significantly correlated with AIx at immediately after exercise but not with AIx at rest. The LVOT Doppler pattern may be sensitive parameters for assessing dynamic arterial compliance. Among the various LVOT Doppler parameters, DT/AT showed the best correlation with Aix.