Figure 9: Bar graph of immediate and follow-up results after balloon angioplasty of aortic coarctation. Peak-to peak systolic pressure gradients across the coarctation in mmHg (mean + SEM) are shown. Note significant (p < 0.001) drop in the gradient following balloon angioplasty (Pre, prior to vs. Post, immediately following). The gradient increases (p < 0.05) slightly at a mean follow-up to 14 mo (range, 4 to 56 mo). However, these values are lower (p < 0001) than prior to angioplasty. At late follow-up (LFU) (median 5 years) following balloon angioplasty, blood pressure-measured arm-leg peak pressure difference is lower than catheterization measured peak gradients prior to (p< 0.001) balloon angioplasty and those obtained at intermediateterm follow-up (p < 0.01). Mean + standard error of mean (SEM) are shown. N indicated the number of patients undergoing balloon angioplasty.