Yield of diagnostic testing in evaluating etiology and end organ effects of pediatric hypertension.

BACKGROUND: Current recommendations regarding the utility of diagnostic investigations for pediatric hypertension are based on limited evidence, leading to wide practice variation. The objective of this study was to characterize the cohort of children that may benefit from secondary hypertension workup, and determine the diagnostic yield of investigations. METHODS: This was a single-center, retrospective cohort study of 169 children aged 1-18 years referred between 2000 and 2015, to a tertiary pediatric nephrology center in Canada, for evaluation of hypertension. The number of investigations completed, abnormal findings, and diagnostic findings that helped establish hypertension etiology was determined. RESULTS: 56 children were diagnosed with primary and 72 children with secondary hypertension in the outpatient setting. Secondary hypertension was predominant at all ages except for obese adolescents ≥ 12 years. Half of children with traditional risk factors for primary hypertension, including obesity, were diagnosed with secondary hypertension. Kidney ultrasound had the highest yield of diagnostic results (19.8%), with no difference in yield between age groups (P = 0.19). Lipid profile had a high yield of abnormal results (25.4%) as part of cardiovascular risk assessment but was only abnormal in overweight/obese children. Echocardiogram had a high yield for identification of target-organ effects in hypertensive children (33.3%). CONCLUSION: A simplified secondary hypertension workup should be considered for all hypertensive children and adolescents. High yield investigations include a kidney ultrasound, lipid profile for overweight/obese children, and echocardiograms for assessment of target-organ damage. Further testing could be considered based on results of initial investigations for the most cost-effective management. A higher resolution version of the Graphical abstract is available as Supplementary information.

Approach to Diagnosis and Management of Hypertension: A Comprehensive and Combined Pediatric and Adult Perspective.

The global prevalence of primary hypertension has been increasing both in children and in the adolescent and adult populations and can be attributed to changes in lifestyle factors with an obesity epidemic, increased salt consumption, and sedentary lifestyles. Childhood blood pressure is the strongest predictor of adult hypertension. Although hypertension in adults is associated strongly with an increased risk for cardiovascular disease, chronic kidney disease, and mortality, outcomes in children are defined less clearly. In adults, major guidelines agree on a threshold of less than 120/80 mm Hg as the optimal blood pressure (BP) and recommend a target of less than 130/80 mm Hg for treatment in most cases. In children, international pediatric guidelines recommend using thresholds based on the normative distribution of BP in healthy normal-weight children. Out-of-office BP assessment is extremely useful for confirming the diagnosis of hypertension and monitoring response to treatment. Lifestyle modifications are instrumental whether coupled or not with pharmacologic management. New agents such as nonsteroidal mineralocorticoid-receptor antagonists, aminopeptidase A inhibitors, aldosterone synthase inhibitors, and dual endothelin antagonists hold significant promise for resistant hypertension. The transition from pediatric to adult care can be challenging and requires careful planning and effective coordination within a multidisciplinary team that includes patients and their families, and pediatric and adult providers.

Local field potentials are local events in the mouse auditory cortex.

Local field potentials (LFPs) and spikes (SPKs) sampled at the thalamocortical recipient layers represent the inputs from the thalamus and outputs to other layers. Previous studies have shown that SPK-constructed receptive fields (RFSPK) of cortical neurons are much smaller than LFP-constructed RFs (RFLFP). The difference in cortical RFLFP and RFSPK is therefore a plausible indication of local networking. The presence of a boarder RFLFP appears due to contamination, to some degree, from remote sites. Our studies of the mouse primary auditory cortex show that the best frequencies and minimum thresholds of RFSPK and RFLFP were similar. We also observed that the RFLFP area was only slightly larger than the RFSPK area, a very different finding from previous reports. The bandwidth of RFLFP was slightly broader than that of RFSPK at all levels. These data do not support the explanation that bioelectrical signals from distant sites impact on cortical LFP through volume conduction. That the cortical LFP represents a local event is further supported by comparisons of RFSPK and RFLFP after cortical inhibition by muscimol and cortical disinhibition by bicuculine. We conclude that the difference between RFSPK (output of cortical neurons) and RFLFP (input of cortical neurons) results from intracortical processing, including cortical lateral inhibition and excitation.