Andersons pediatric cardiology 1603

have been reported to develop nocturnal hypertension and the nondipping state, as opposed to patients with primary hypertension who may maintain their dipping status.76 The morning surge as described in adults,75,77,78 however, is not usually reported in children Normal Blood Pressure in Childhood A large number of studies have been undertaken to establish the range of blood pressure found in normal children,79–81 with the results for boys summarized in Fig 60.1 As a general rule, a steady increase has been observed with age, with no significant difference between the sexes during childhood Most studies, unfortunately, differ in some respect, for example in the sizes of cuff used, with measurements taken with the patient sitting or supine, using different end points for diastolic pressure, and so on FIG 60.1 The 95th centiles for systolic and diastolic blood pressure in boys taken from various sources Data from the Rochester (Minnesota) study,29 including data from the Muscatine study128; a Scandinavian study81; the Bogalusa study84; the Zurich study80; and the Londe study.79 The conditions and measurement parameters varied Children were seated, except in the study of Londe, where they were supine.79 The widths of the cuffs used were 9 and 13 cm (Scandinavian),81 two-thirds of upper arm (Londe),79 at least two-thirds of upper arm (Rochester),29 mostly 10 and 12.5 cm (Bogalusa),84 and the largest possible (Zurich).80 Standard mercury sphygmomanometers were used except in the Zurich study, where random-zero manometers were used There is an overlap between use of phase 4, muffling of sounds, and phase 5, cessation of sounds (From Leuman EP Blood pressure and hypertension in childhood and adolescence In: Frick P, von Harneck GA, Martini GA, et al., eds Advances in Internal Medicine and Pediatrics Berlin: Springer; 1979:109– 183.) These differences in technique make it difficult to interpret apparent differences between ethnic groups Adult black individuals have an increased prevalence of hypertension and damage to target organs when compared with whites.82 Nigerian children were found to have higher pressures than black American children.83 Higher values for black than white children might be expected in view of the higher prevalence of hypertension in black adults These were reported by the Bogalusa study,84 but similar,30,85–88 lower,89–91 and no difference in values92 have also been reported A significant increase in the proportion of hypertensive 18-year-old black adolescents has also been reported,93,94 albeit that another study95 found no difference in the reninangiotensin-aldosterone system when comparing black and white children and adolescents It has been suggested that the evaluation of blood pressure in an individual should be based on height and weight rather than age.85 It is not clear whether sexual maturation has an effect, independent of body mass, on blood pressure.79 Obesity poses special problems because of the essential requirement for an adequate cuff in making measurements Where adequate sizes have been used, obese adolescents have been found to have a higher incidence of hypertension.96 Corrections have been made according to the circumference of the arm and the size of the cuff used in the measurement (see Table 60.1).97 The deleterious influence of salt on blood pressure in children has become clearer, and is discussed briefly later in this chapter No clinically significant difference seems apparent in blood pressure between bottle- and breast-fed infants.98–101 Normal Values for Blood Pressure Measured in the Clinic Pressures during childhood vary physiologically with gender, age, and height The practicing clinician requires standards with which to compare the blood pressure of individual patients (see Tables 60.2 and 60.3) In a recent report of the European Society of Hypertension,36 data from the Fourth Report from the working group of the National High Blood Pressure Education Program in the United States9 have been used to define hypertension, high-normal (previously called “prehypertension”), and normotension In contrast to previous definitions, adolescents 16 years or older would be considered hypertensive using absolute cutoff of BP values like adults, defining high-normal (130–139 mm Hg systolic and 85–89 mm Hg diastolic) and hypertension (≥140/90 mm Hg).36 Updated guidelines from the American Academy of Pediatrics, as discussed previously, show similar although not identical categorization.37 The Fourth Report from the working group of the National High Blood Pressure Education Program in the United States provides 50th, 90th, 95th, and 99th percentiles for pressures obtained by auscultation in formats specific for gender, age, and height.9 It provides data over and above those from the previous reports of the Task Force on Blood Pressure Control in Children,30,32 giving comprehensive values for seven different centiles for height at each age from 1 to 17 years, as shown in Table 60.2 for boys and Table 60.3 for girls In addition, the new data describe stages of hypertension, defining normotension as below the 90th percentile, high-normal as between the 90th and 95th percentiles, the first stage of hypertension as between the 95th and 99th percentiles plus 5 mm Hg, and the second stage of hypertension as greater than the 99th percentile plus 5 mm Hg, similar to the seventh report of the joint national committee.102 It provides guidance on the speed at which evaluation, treatment, and referral should be made in a child with elevated blood pressure The age- and genderspecific percentiles for blood pressure in girls and boys from birth to 12 months of age are shown in Figs 60.2 and 60.3, respectively  ... adolescence In: Frick P, von Harneck GA, Martini GA, et al., eds Advances in Internal Medicine and Pediatrics Berlin: Springer; 1979:109– 183.) These differences in technique make it difficult to interpret apparent... and 85–89 mm Hg diastolic) and hypertension (≥140/90 mm Hg).36 Updated guidelines from the American Academy of Pediatrics, as discussed previously, show similar although not identical categorization.37 The Fourth Report from the working group of the National High Blood