Quantitative echocardiographic characterization of abdominal aortic pulsatility in children with coarctation.

Obstructed blood flow due to aortic coarctation leads to a pressure drop and loss of the pulse wave distal to the stenosis. This can be observed by echocardiography as typically decreased pulsatility of the abdominal aorta after cardiac systole. Our study intended to quantitatively describe abnormal abdominal aortic pulsatility in children with coarctation. A standardized M-mode echocardiographic study of the abdominal aorta was prospectively performed with measurements of minimum and maximum abdominal aortic diameters and the corresponding time intervals during the cardiac cycle. Of these measurements the percent increase in aortic diameter was calculated and this increase was indexed to a unit of time. A total of 50 children were studied: 27 had angiographically proven severe coarctation (19 unoperated and 8 operated children with recurrent coarctation) with a mean minimum aortic lumen of 32+/-6% of the prestenotic aortic lumen. A total of 23 healthy children were studied as a control group. Children with significant coarctation differed from normals in all parameters evaluated. Two calculated values, the percent increase in aortic diameter (5-25% in patients and 27-50% in normals) and the percent increase per unit of time (18-108%/s in patients and 154-288%/s in normals) allowed for a clear discrimination between patients and normals with no overlap of individual values. Quantitative characterization of abnormal pulsatility of the abdominal aorta due to the loss of pulse wave pressure clearly discriminated children with angiographically proven significant coarctation from normal controls.