Abstracts / Journal of the American Society of Hypertension 8(4S) (2014) e129–e131 Charleston, SC, United States; SC, United States
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MUSC Children’s Hospital, Charleston,
Background: Intravenous (IV) hydralazine is frequently used for the treatment of elevated blood pressure (BP) in hospitalized children. Its safety and efficacy has not been examined. Methods: A retrospective chart review of IV hydralazine use in hospitalized children (birth to 17 years) over a 3-year period. Demographic data, adverse effects (AE), and BP and heart rate (HR) prior to and after each first dose were collected. Results: Included were 110 admissions; 77 children received the recommended dose. Mean age was 8.5 5.4 years, 33% were male, and 32.5% were white. Pre-dose systolic and diastolic BP indexes were 1.3 and 1.2, respectively. Median systolic and diastolic BP reduction was 8.5% and 11.5%, respectively. Sixteen (21%) achieved systolic or diastolic BP reduction by 25%. Eight (10.3%) achieved BP <95th percentile for age, sex, and height after one dose. Seven (9%) had documented AE. HR increased by a median of 3.5%. In multivariable models examining percent change in systolic and diastolic BP, male gender was significantly associated with change in systolic BP. Conclusions: In hospitalized children in this study, 21% achieved a reduction of systolic or diastolic BP by 25%. IV hydralazine was well tolerated. Keywords: pediatrics; hydralazine; hospitalized; elevated blood pressure P-235 Sedentary behavior is a risk factor for higher exercise blood pressure independent of moderate-to-vigorous physical activity (MVPA) in young subjects Burkhard Weisser, Claudia Hacke, Manfred Wegner. Christian-AlbrechtsUniversity, Kiel, Germany There are indications that sedentary behavior and exercise time might be separate and different cardiovascular risk factors as opposed to the concept that the risk is represented along a continuum depending on the amount of activity. In the present study, the influences of both sedentary behavior (screen time) and physical activity on resting and exercise blood pressure (BP) were investigated in 532 subjects aged 12-17 years. Exercise BP was studied using a standardized cycle ergometer exercise test. Systolic BP was measured at 1.5 Watt / kg body weight. Fitness was determined as the physical working capacity at a heart rate of 170/min. (PWC 170). Screen time and moderate-to-vigorous physical activity (MVPA) were retrieved through a questionnaire. The subjects were classified according to their screen time, either 2 h / day (as recommended) or > 2 h / day. Resting BP was lower (-2.3 mmHg, p¼0.03) in the group with lower screen time ( 2 h / day) adjusted according to age, sex, height and BMI (111.9 11.3 vs. 114.2 11.3 mmHg). After further adjustment for fitness, the difference was no longer significant. In contrast, systolic exercise BP remained significantly lower (-3.7 mmHg, p¼0.02) after correction for all variables (148.1 16.9 vs. 151.8 16.9 mmHg). Furthermore, the influence of screen time on exercise BP was independent of physical activity (p¼0.023).
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Our data support the concept that sitting (or totally inactive) time might be a risk factor for higher BP independent of amount of physical activity. Thus, it might be speculated that activity and inactivity might not be the extremes of the same continuum but could be two different or separate risk factors, at least for exercise BP in adolescents. In addition, it is interesting to note that in this group, lifestyle parameters of activity, sedentary behavior and fitness have a greater effect on exercise BP than on resting BP. Keywords: exercise blood pressure; screen time; adolescents
P-236 The screening utility of simplified blood pressure tables to identify the need for further blood pressure assessment in children Ajay P. Sharma, Javed Mohammed, Benson Thomas, Ram N. Singh, Guido Filler. Western University, London Health Sciences Centre, London, ON, Canada Background: The reported significant under-diagnosis of hypertension (z80%) in children, despite their recorded abnormal casual blood pressures (BP), was attributed to the challenges in BP interpretation while using multiple BP thresholds (those account for an individual’s age, gender and height percentile) on the fourth report BP tables. To facilitate the appreciation of abnormal BP, the simplified BP tables, containing single BP thresholds for a particular age and gender (corresponding to 90th BP and 5th height percentiles on the fourth report BP tables), eliminated the need of accounting for individual’s height percentile while interpreting BP. The screening utility of the simplified BP tables to decide the need for further BP assessment has remained untested. Methods: In 155 subjects, aged 5 to 18 years, referred for 24-hour ambulatory BP monitoring (ABPM), we analyzed the accuracy of abnormal casual BP as per the simplified BP tables for correctly identifying BP categories as per the fourth report BP tables (classified according to the 90th BP and individual’s actual height percentile) and as per ABPM (classified according to the ABPM reference intervals). Results: The simplified BP tables correctly identified all the BP labeled as abnormal by the fourth report BP tables. After accounting for the individual’s height percentile, 33% of the systolic and 5% of the diastolic BP labeled as abnormal by the simplified BP tables were deemed normal by the fourth report BP tables (kappa: 0.72 for systolic BP, and 0.92 for diastolic BP). The simplified BP tables showed similar accuracy as that of the fourth report BP tables for correctly identifying both abnormal and normal ABPM BP (P>0.05; equivalent sensitivity, specificity, predictive values and likelihood ratios). Conclusions: The simplified BP tables can serve as a simple and accurate screening tool to reduce the under-diagnosis of hypertension by identifying abnormal BP those need further BP evaluation as per the fourth report BP tables or referral for ABPM assessment. Keywords: ambulatory blood pressure monitoring; fourth report blood pressure tables; simplified blood pressure tables; under-diagnosis of hypertension in children