A simple method of measuring thoracic aortic pulse wave velocity in children: methods and normal values.

BACKGROUND: The objective of this study was to define a simple method of measuring thoracic aortic pulse-wave velocity (PWV) using only an aortic length regression equation based on the subject's height and two pulsed Doppler recordings of the aorta. METHODS: The thoracic aortas of 80 subjects (age range, 0-20 years) were measured retrospectively by direct echocardiographic visualization. A simple linear regression equation for thoracic aortic length on the basis of height was derived. PWV was defined as the thoracic aortic length, derived from the subject's height, divided by pulse transit time. Pulse transit time was defined as the difference in the time of onset of two pulsed Doppler recordings placed at the level of the aortic valve leaflet tips and the diaphragm. Normative data were retrospectively defined in 206 children. RESULTS: Thoracic aortic length was linearly related to subject height by the equation thoracic aortic length (cm)=1.7 cm+0.1 (height [cm]) (R2=0.98, P<.0001). Thoracic aortic PWV was independent of age (median, 3.04 m/s). CONCLUSION: Thoracic aortic PWV can be simply calculated from a routine echocardiogram, it is constant throughout childhood, and it may improve the assessment of left ventricular load.

Left ventricular mass index in children with white coat hypertension.

OBJECTIVES: To determine whether children with white coat hypertension (WCH) have evidence of target-organ damage by comparing the left ventricular mass index (LVMI) of subjects with WCH with that of matched normotensive and hypertensive controls. STUDY DESIGN: Each subject in the WCH group was matched by body mass index (BMI; +/- 10%), age (+/- 1 year), and sex to a normotensive control and a hypertensive control. Echocardiograms were reviewed to determine the LVMI for each subject. These triple matches were analyzed using repeated-measures analysis of variance to detect differences in LVMI among the 3 groups. RESULTS: A total of 27 matched triplets were established. The groups were comparable for sex, age, and BMI. Mean LVMI was 29.2 g/m(2.7) for the normotensive group, 32.3 g/m(2.7) for the WCH group, and 35.1 g/m(2.7) for the sustained hypertensive group (normotensive vs WCH, P = .028; WCH vs sustained hypertension, P = .07). Left ventricular hypertrophy was not present in any subject in the normotensive or WCH groups, but was found in 26% of the sustained hypertensive subjects (P < .001). CONCLUSIONS: After controlling closely for BMI, the LVMI in the subjects with WCH was between that of the normotensives and sustained hypertensives, suggesting that WCH may be associated with hypertensive end-organ effects.

Young-Simpson syndrome (YSS), a variant of del(1)(p36) syndrome?

The Young-Simpson syndrome (YSS) and 1p36 deletion syndrome are both characterized by facial and heart abnormalities, congenital hypothyroidism, and severe growth and developmental retardation. However, the YSS is characterized by the presence of blepharophimosis and epicanthus inversus, findings not described in monosomy 1p36 patients. We describe a girl with YSS, who presented with the typical facial findings, global retardation, congenital hypothyroidism, and congenital dilated cardiomyopathy. Comparative genomic hybridization chromosomal microarray analysis showed a 1p36.3 deletion, a finding not previously reported in other YSS cases. We propose that YSS is a variant of the 1p36 deletion syndrome.

Effects of childhood primary hypertension on carotid intima media thickness: a matched controlled study.

To determine whether carotid intima media thickness is increased in children with primary hypertension, the current study compared carotid intima media thickness in hypertensive children with that of normotensive control subjects matched closely for body mass index and determined the relationship between carotid intima media thickness and hypertension severity determined by ambulatory blood pressure monitoring. Children with newly diagnosed office hypertension (n=28) had carotid intima media thickness, left ventricular mass index, and ambulatory blood pressure monitoring performed. Carotid intima media thickness was performed in normotensive control subjects (n=28) matched pairwise to hypertensive subjects for age (+/-1 year), gender, and body mass index (+/-10%). Eighty-two percent of subjects were overweight or obese (body mass index > or =85th percentile). The median carotid intima media thickness of hypertensive subjects was greater than that of matched controls (0.67 versus 0.63 mm; P=0.045). In the hypertensive subjects, carotid intima media thickness correlated strongly with several ambulatory blood pressure monitoring parameters, with the strongest correlation for daytime systolic blood pressure index (r=0.57; P=0.003). In the hypertensive group, the prevalence of left ventricular hypertrophy was 32%, but unlike carotid intima media thickness, left ventricular mass index did not correlate with ambulatory blood pressure monitoring. Together, the findings that hypertensive subjects had increased carotid intima media thickness compared with matched controls and that higher carotid intima media thickness correlated with more severe hypertension by ambulatory blood pressure monitoring provide strong evidence that carotid intima media thickness is increased in childhood primary hypertension, independent of the effects of obesity.