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Figure 4 Peak Gradient as a Function of Age in Patients With First Surgery Before and After 4 Years of Age

Points represent median peak gradient at initial diagnosis, preoperative echocardiogram, early postoperative echocardiogram, and latest follow-up plotted against median age at these events. Error bars represent the interquartile range around median peak gradients at each time point. Note that patients who were operated on earlier (blue) began with a lower peak gradient that rose more rapidly to a value equal to that in patients with a later age at operation (red), suggesting a more rapidly progressing pathology.