Using echocardiographic quantification of aortic pulsatility distal to the site of the surgical anastomosis, we evaluated whether the preoperatively impaired poststenotic aortic pulsatility returned to normal after repair of coarctation with a hemodynamically ideal result. Patients who underwent repair of aortic coarctation without residual obstruction were compared to a matched group of normal children. A standardized M-mode echocardiographic evaluation of the aorta at the diaphragmatic level was performed for all patients. Measurements consisted of maximum and minimum aortic diameters, time intervals, and a calculated pulsatility index. Compared to normal children (n = 19), 20 children with operated coarctation and with a hemodynamically ideal result showed a significantly smaller increase in aortic diameter in systole (mean of 29 ± 7% in patients versus 37 ± 7% in normals; p < 0.01). In contrast to patients with coarctation in whom the maximum aortic distension is reached much later during the cardiac cycle, hemodynamically normalized, operated patients in our study had no such delay (maximum aortic pulsation at 28% of cardiac cycle time compared to 27% in normals; p = not significant). The pulsatility index of the poststenotic aorta was clearly lower in operated children (mean, 130 ± 50%/sec) compared to a normal mean value of 202 ± 33%/sec but was still significantly higher than that in patients with unoperated coarctation, who showed a low mean value of 51 ± 24%/sec (p < 0.01). After correction of aortic coarctation with a hemodynamically ideal result, the pulsatility of the poststenotic aorta, severely impaired prior to repair, did not return to normal during the observation period in the patients studie