Mechanical properties of the common carotid artery in Williams syndrome.
OBJECTIVE
To determine whether arterial wall hypertrophy in elastic arteries was associated with alteration in their mechanical properties in young patients with Williams syndrome.


METHODS
Arterial pressure and intima-media thickness, cross sectional compliance, distensibility, circumferential wall stress, and incremental elastic modulus of the common carotid artery were measured non-invasively in 21 Williams patients (mean (SD) age 8.5 (4) years) and 21 children of similar age.


RESULTS
Systolic and diastolic blood pressures were higher in Williams patients (125/66 v 113/60 mm Hg, p < 0.05). The mean (SD) intima-media thickness was increased in Williams patients, at 0.6 (0.07) v 0.5 (0.03) mm (p < 0. 001). Normotensive Williams patients had a lower circumferential wall stress (2.1 (0.5) v 3.0 (0.7) mm Hg, p < 0.01), a higher distensibility (1.1 (0.3) v 0.8 (0.3) mm Hg(-1).10(-2), p < 0.01), similar cross sectional compliance (0.14 (0.04) v 0.15 (0.05) mm(2). mm Hg(-1), p > 0.05), and lower incremental elastic modulus (7.4 (2. 0) v 14.0 (5.0) mm Hg.10(2); p < 0.001).


CONCLUSIONS
The compliance of the large elastic arteries is not modified in Williams syndrome, even though increased intima-media thickness and lower arterial stiffness are consistent features. Therefore systemic hypertension cannot be attributed to impaired compliance of the arterial tree in this condition.
Aggoun
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INSERM 0016 and Service de Cardiologie Pédiatrique, Hôpital Necker-Enfants Malades, 149 rue de Sèvres 75743, Paris Cedex 15, France.
Sidi
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Levy
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Lyonnet
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Kachaner
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Bonnet
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D000293:Adolescent; D000328:Adult; D017536:Carotid Artery, Common / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D004548:Elasticity; D006801:Humans; D018709:Statistics, Nonparametric; D018980:Williams Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology*