No abstract

SUMMARY This report reviews the results of six large blood pressure surreys done on pediatric populations and points out factors responsible for differences in the blood pressure norms. Tbe studies were selected on the basis of there being recent examinations of large numbers of children. Important differences in mean systolic pressures and 95th percentile rallies were found among the studies, which may be attributed to: 1) actual differences among the populations; 2) biases due to methodological differences; or 3) increased sampling variability with small sample sizes. Actual differences in pressures among tbe populations surreyed may be due to differences in geographic location, radal composition, or average body sizes. Discrepancies due to methodological biases'may have occurred because of associated venlpuncture or exercise stress on the day of the examination; differences in selection of blood pressure cuff sizes; differences in the number of measurements averaged. In several studies, small sample sizes for each age-race-sex subclass accounted for considerable variability of the 95th percentile value. Tbe implication of this analysis is that before the 95th percentile norms for children of different ages, races, and sexes can be more firmly established, it is necessary to collect larger sample sizes controlling for known biasing factors and using a standardized methodology.

Normal kidney length was measured on the excretory urogram in 262 children 0 to 14.5 years of age (422 kidneys). While mean values were similar to those in the literature, the standard deviation (0.785 cm) was much lower than that reported previously.

133 Univ. of Texas Health Sci. Ctr, h p t . of Fed. Dallas The purpose of t h i s study was t o determine i f blood pressures (BP) during dynamic exercise (DYN EX) and isometric exercise (IS0 EX) i n hypertensive adolescents a r e useful i n identifying those destined to have persistent blood pressure elevations. All 62 subjects had pressures above the 95th percentile on three 8th grade exams. Dynamic and isometric s t r e s s t e s t s were performed i n the 9th grade and resting BP was remeasured on 3 exams i n the 10th grade. Students were c l a s s i f i e d on the basis of t h e i r 10th grade BP: I. Normal 145f 10166f 12 196f20165f35 145+10/93~11 Stepwise regression was used to correlate the BP a t r e s t and during exercise with 10th grade r e s t i n g BP. Systolic BP during DYN EX and d i a s t o l i c BP during IS0 EX had s i g n i f i c a n t correlations with 10th grade BP, p<.007 and p<.05 respectively. However, comparing exercise pressures with r e s t i n g pressures, the former accounted f o r only an additional 5% of the variance of the 10th grade pressures. Therefore, i f hypertension i s suspected on the basis of three resting pressures doing exercise t e s t i n g adds l i t t l e t o the accuracy of predicting blood pressure s t a t u s one year l a t e r . t i c valve. U t i l izing an angiographic method of en face viewing of the a o r t i c valve a precise evaluation of the anatomic configuration of the a o r t i c valve has been shown by us t o be possible. Employing t h i s technique of orifice-view aortography two d i s t i n c t a o r t i c valve deformities have been identified when the a o r t i c valve i s bicuspid:(1)inequality of cusp s i z e and (2) near-equality of cusp s i z e as determined by planimetry of the valve during motion picture projection. W e have studied a group of 10 young patients with a congenital equally bicuspid a o r t i c valve. When these patients were subjected t o M-mode echocardiography, 3 revealed features of a normal a o r t i c valve with no e c c e n t r i c i t y of the l i n e of closure within the echographic boundaries of the a o r t i c lumen and absence of multiple echos; in an additional patient the findings were equivocal f a i l i n g t o allow d e f i n i t i v e diagnosis. From t h i s c o r r e l a t i v e evaluation we conclude t h a t M-mode echocardiography alone i s not a r e l i a b l e indicator of a o r t i c valve bicuspidization when there i s near-equality of the cusp s i z e . This finding has c l i n i c a l implications r e l a t i n g t o those laboratories employing only M-mode echocardiography f o r routine cardiovascular evaluation. Because of t h e known differences between newborn and adult myocardial t i s s u e , t h i s study was undertaken t o evaluate by echocardiography the cardiovascular condition o f 1 3 hypothyroid infants (HI), aged 3 t o 9 weeks. Left ventricular (LV) s y s t o l i c and d i a s t o l i c dimdsions, posterior wall thickness, end diastol i c ( E N and s y s t o l i c volumes were all s i ...

The purpose of this study was to determine whether values of blood pressure during exercise help predict which adolescents are prone to maintain high blood pressure. Dynamic and isometric exercise stress tests were performed on 131 adolescents who had had systolic or diastolic pressures greater than the 95th percentile on three examinations the previous year. Follow-up blood pressures were measured 1 year after the stress testing, and outcomes were classified on the basis of the blood pressure status that year. Stepwise regression analysis was used to examine the association between earlier blood pressures and exercise pressures with outcome pressures. In both male and female adolescents, the average resting systolic pressure on the earlier survey was the best predictor of systolic pressure 2 years later. Blood pressures and heart rates during dynamic and isometric exercise did not significantly contribute to the models' prediction of future systolic or diastolic pressures. The data suggest that exercise stress testing is not a valid method for predicting youths whose blood pressures will remain elevated over the next 1 to 2 years.