The aortic root in subaortic stenosis

This study investigated the size of the aortic root (AoR) and its effect on surgical outcome in patients with fixed subaortic stenosis. The diameter of the AoR was measured in two groups by means of two-dimensional echocardiography. Group A consisted of 138 normal subjects, aged 3 weeks to 20 years (mean 7.5 years). Group B consisted of 28 patients with fixed subaortic stenosis, aged 1.5 to 18 years (mean 9.5 years), 21 of whom had undergone surgical resection of the stenosis. Normal values and growth curves for AoR diameter were obtained from patients in group A. There was marked retardation of growth of the AoR among patients in group B, with seven patients having a small AoR diameter (less than 2 standard deviations). Postoperative gradients had a high correlation with the small size of diameter of the AoR (r = -0.84). In fixed subaortic stenosis the AoR may be small (25%). The presence of a small AoR has a marked effect on the optimal relief of fixed subaortic stenosis. The diameter of the AoR should be measured preoperatively, inasmuch as special surgical techniques may be required.