title: Altered baroreceptor function in children with systolic hypertension after coarctation repair.
abstract: To determine whether altered baroreceptor function may contribute to systemic hypertension after coarctation of the aorta (C of A) repair, baroreceptor function was evaluated in 6 children with repaired C of A mild arm systolic hypertension. Data were compared with those from 7 normotensive control children with hemodynamically mild heart disease. Age at C of A repair averaged 9.9 +/- 3.1 years (mean +/- standard deviation [SD]). Arm systolic pressure was 143.8 +/- 2.9 mm Hg in the C of A repair group, compared with 118.3 +/- 9.9 for control subjects (p less than 0.001). At catheterization, steady-state sigmoidal baroreceptor function curves relating mean arterial pressure to R-R interval were derived by increasing and decreasing mean arterial pressure with small injections of phenylephrine and nitroprusside. Compared with control subjects, the baroreceptor function curves of children with repaired C of A (1) are reset about a higher baseline mean arterial pressure (108.8 +/- 6.6 versus 90.3 +/- 8.6 mm Hg, p less than 0.01), (2) have a decreased slope (7.9 +/- 3.7 versus 17.4 +/- 3.6 ms/mm Hg, p less than 0.001), and (3) have a diminished R-R interval range (246.7 +/- 81.5 versus 535.7 +/- 97.2 ms, p less than 0.001). Thus, in children with hypertension after C of A repair, the baroreflex is reset to an elevated mean arterial pressure level and has a diminished sensitivity to changes in arterial pressure.
mesh_terms: D000293:Adolescent; D000328:Adult; D001017:Aortic Coarctation / Q000601:surgery*; D001132:Arm / Q000098:blood supply; D006328:Cardiac Catheterization; D002648:Child; D005080:Exercise Test; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D011183:Postoperative Complications; D011311:Pressoreceptors / Q000503:physiopathology*