Increased nocturnal heart rate and wave reflection are early markers of cardiovascular disease in Williams-Beuren syndrome children.
OBJECTIVE
Williams-Beuren syndrome (WBS) is a genetic disorder that involves elastin gene causing cardiovascular abnormalities and increased risk. However, data on arterial function in these patients are only few and conflicting. Aim of this study was to evaluate dynamic behaviour of central and peripheral blood pressure (BP) and arterial stiffness parameters early in the course of WBS.


METHODS
We enrolled 19 WBS paediatric patients (age 13 ± 4 years) and 23 age, height and BP-matched controls (10 ± 4 years). We evaluated 24-h ambulatory BP values via an ambulatory blood pressure monitoring (ABPM) system (Mobil-O-Graph) also capable to calculate 24-h central BP and 24-h arterial stiffness parameters. Carotid-femoral PWV (cf-PWV) was assessed in all WBS individuals (Complior).


RESULTS
BP values were similar in WBS and control, during the daytime and the night-time. The same behaviour applies to 24-h central BP. However, during the night, WBS showed heart rate values (HR; 78 ± 10 vs. 71 ± 9 bpm; P < 0.03), augmentation index (Aix; 24.6 ± 13.5% vs. 16.5 ± 8.9%; P = 0.03) and reflection magnitude (68 5.8 vs. 63.5 8.1; P = 0.02) higher than controls. The HR, Aix and reflection magnitude reduction in the day-night shift was lower in WBS than in controls. Cf-PWV in WBS children did not differ when compared with their normalized expected value.


CONCLUSIONS
In WBS children, the higher night-time HR, Aix and reflection magnitude and their impaired physiological reduction in the day-night shift suggests an abnormal sympathetic cardiovascular control, an augmented wave reflection and an increase in small arteries resistance. These alterations possibly due to a sympathetic overactivity can be regarded as earlier hallmarks of cardiovascular dysfunction in these patients.
aMilano-Bicocca University and Cardiologia IV, Cardiovascular A. De Gasperis Department, Niguarda Ca'Granda Hospital, Milan, Italy bAustrian Institute of Technology, Wien, Austria cPediatric Division Göttingen, Göttingen dI.E.M., Stolberg, Germany ePediatric Clinic Division, Milano-Bicocca University and San Gerardo Hospital, Monza fMilano-Bicocca University and Istituto Auxologico Italiano, Milan, Italy.
Alessandro
A
Maloberti
Francesca
F
Cesana
Bernhard
B
Hametner
Dario
D
Dozio
Paolo
P
Villa
Martin
M
Hulpke-Wette
Achim
A
Schwarz
Angelo
A
Selicorni
Siegfried
S
Wassertheurer
Giuseppe
G
Mancia
Cristina
C
Giannattasio
D000293:Adolescent; D001794:Blood Pressure; D001795:Blood Pressure Determination; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000209:etiology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D059289:Vascular Stiffness; D018980:Williams Syndrome / Q000150:complications / Q000503:physiopathology*