Background: Based on the hypothesis that vascular dysfunction in the ascending aorta can cause morbidity, we undertook this study on the elastic properties of ascending aorta and left ventricular(LV) function in young children who receive d coarctoplasty in early infancy. Methods: Blood pressures(BP) in the right arm and ascending aortic internal diameters determined by M-mode ultrasound at rest and after exercise were measured in 25 patients(mean age, 6.4±3 years) and 22 control subjects(mean age, 5.8±2.4 years). Ascending aortic stiffness index and distensibility were calculated using BP measurements and ascending aortic inter nal diameters. In addition, LV parameters(systolic and diastolic function, mass index) were evaluated. Results: Compared with control subjects, patients had inc reased stiffness index(at rest: 4.87±1.94 versus 3.57±1.19, P=0.021; after exe rcise: 4.33±1.91 versus 3.2±1.26, P=0.034) and decreased distensibility(at res t: 6.90±3.15 versus 8.72±2.77, P=0.02; after exercise: 5.69±2.39 versus 7.88 ±3.44 cm2 dyn-1 10 -6, P=0.023). BP and LV parameters showed no consistent di fferences between the two groups. In patients, distensibility was significantly correlated with systolic BP(at rest: P=0.008; after exercise: P=0.014) and pulse pressure(at rest: P=0.013; after exercise: P=0.001). Conclusions: This study su ggests that vasculopathy of ascending aorta is possible in some young children d espite early correction. However, long-term tracking study is needed to clarify the significance of the study. Background: Based on the hypothesis that vascular dysfunction in the ascending aorta can cause morbidity, we undertook this study on the elastic properties of ascending aorta and left ventricular (LV) function in young children who received d coarctoplasty in early infancy. Methods: Blood pressure (BP) in the right arm and ascending aortic internal diameters determined by M-mode ultrasound at rest and after exercise were measured in 25 patients (mean age, 6.4 ± 3 years) and 22 control subjects (mean age, 5.8 ± 2.4 years) Ascending aortic stiffness index and distensibility were calculated using BP measurements and ascending aortic inter-nal diameters. at rest: 4.87 ± 1.94 versus 3.57 ± 1.19, P = 0.021; after exe rcise: 4.33 ± 1.91 versus 3.2 ± 1.26, P = 0.034) and decreased distensibility (at res t: 6.90 ± 3.15 versus 8.72 ± 2.77, P = 0.0 2; after exercise: 5.69 ± 2.39 versus 7.88 ± 3.44 cm2 dyn-1 10 -6, P = 0.023). BP and LV parameters showed no consistent di fferences between the two groups. In patients, distensibility was significantly correlated with systolic BP ( at rest: P = 0.008; after exercise: P = 0.014) and pulse pressure (at rest: P = 0.013; after exercise: P = 0.001). Conclusions: This study su ggests that vasculopathy of ascending aorta is possible in some young children However, long-term tracking study is needed to clarify the significance of the study.