Background Central systolic and pulse pressures are stronger predictors of cardiovascular risk and hypertensive organ damage than brachial blood pressure. It is suggested that isolated systolic hypertension typically seen in adolescents is associated with normal central blood pressure and does not lead to organ damage and this phenomenon is called spurious hypertension. Methods We assessed the prevalence of spurious hypertension and analyzed utility of pulse wave analysis as determinant of hypertensive organ damage in 294 children (62 girls; 15.0 ± 2.4 years) diagnosed as primary hypertension. White coat hypertension, ambulatory prehypertension, ambulatory hypertension, and severe ambulatory hypertension were diagnosed in 127, 29, 41, and 97 patients, respectively. Results Normal central blood pressure was found in 100% in patients with white coat hypertension, 93% in pre-hypertensives, 51.2% in those with ambulatory hypertension, and 27.8% with severe ambulatory hypertension ( p = 0.0001). Children with severe ambulatory hypertension had higher central systolic and pulse pressure, pulse wave velocity, and greater prevalence of left ventricular hypertrophy than white coat and prehypertensive children ( p < 0.05). Left ventricular mass index and carotid intima-media thickness correlated with central systolic and pulse pressure ( p < 0.05 for all). Receiver operating curve area was similar for augmentation pressure (0.5836), 24-h ambulatory systolic blood pressure (0.5841), central systolic blood pressure (0.6090), and central pulse pressure (0.5611) as predictors of left ventricular hypertrophy. Conclusions These findings suggest that pulse wave analysis is complementary to ambulatory blood pressure monitoring in assessment of risk of organ damage in hypertensive adolescents.

Background Currently used pediatric kidney length normative values are based on small single-center studies, do not include kidney function assessment, and focus mostly on newborns and infants. We aimed to develop ultrasound-based kidney length normative values derived from a large group of European Caucasian children with normal kidney function. Methods Out of 1,782 children aged 0–19 years, 1,758 individuals with no present or past kidney disease and normal estimated glomerular filtration rate had sonographic assessment of kidney length. The results were correlated with anthropometric parameters and estimated glomerular filtration rate. Kidney length was correlated with age, height, body surface area, and body mass index. Height-related kidney length curves and table were generated using the LMS method. Multivariate regression analysis with collinearity checks was used to evaluate kidney length predictors. Results There was no significant difference in kidney size in relation to height between boys and girls. We found significant (p < 0.001), but clinically unimportant (Cohen’s D effect size = 0.04 and 0.06) differences between prone vs. supine position (mean paired difference = 0.64 mm, 95% CI = 0.49–0.77) and left vs. right kidneys (mean paired difference = 1.03 mm, 95% CI = 0.83–1.21), respectively. For kidney length prediction, the highest coefficient correlation was observed with height (adjusted R2 = 0.87, p < 0.0001). Conclusions We present height-related LMS-percentile curves and tables of kidney length which may serve as normative values for kidney length in children from birth to 19 years of age. The most significant predictor of kidney length was statural height. Graphic Abstract

Background: Left ventricular non-compaction (LVNC) is a rare cardiomyopathy typically involving the left ventricle (LV); however, the right ventricle (RV) can also be affected. This case-control study aimed to assess the morphology and function of LV and RV in children with LVNC. Methods: Sixteen children (13 ± 3 years, six girls) with LVNC were compared with 16 sex- and age-matched controls. LV and RV morphology and function were evaluated in cardiovascular magnetic resonance (CMR) studies. Additionally, LV and RV global radial (GRS), circumferential (GCS), and longitudinal strain (GLS) were assessed using tissue-tracking analysis. Results: Patients with LVNC did not differ from the healthy controls in terms of age, height, weight, and body surface area (BSA). In total, 4/16 subjects with LVNC had mid-wall late gadolinium enhancement (LGE). Compared to the control group, patients with LVNC had higher end-diastolic volume (EDV) indexed for body surface area (BSA), lower ejection fraction (EF), and lower LV strain parameters (all p < 0.05). Children with LVNC also presented with thicker RV apical trabeculation, whereas there were no differences in RV EF and EDV/BSA between the groups. Nevertheless, children with LVNC had impaired RV GRS and GCS (both p < 0.05). Conclusions: LVNC in pediatric patients is associated with LV enlargement and impaired LV systolic function. Additionally, children with LVNC have increased RV trabeculations and subclinical impairment of RV myocardial deformation.

Background: Left ventricular noncompaction cardiomyopathy (LVNC) is a rare cardiac disorder characterised by the presence of a two-layer myocardium with prominent ventricular trabeculation, intertrabecular deep depressions and an increased risk of heart failure, atrial and ventricular arrhythmias and systemic thromboembolic events in affected patients. The heterogeneous molecular aetiology solved in 10%–50% of patients more frequently involves sarcomeric, cytoskeletal or ion channel protein dysfunction—mainly related to causative MYH7, TTN or MYBPC3 variants. The aim of the study was to determine the molecular spectrum of isolated LVNC in a group of children examined in a single paediatric reference centre. Methods: Thirty-one paediatric patients prospectively diagnosed with LVNC by echocardiography and cardiovascular magnetic resonance examination were recruited into the study group. The molecular analysis included next-generation sequencing (gene panel or whole exome) and classic Sanger sequencing. All selected variants with high priority were co-segregated in the available parents. Results: We identified 16 distinct variants in 11 genes in 16 patients (52%), including 10 novel alterations. The most frequent defects in our cohort were found in the genes HCN4 (n = 4), MYH7 (n = 2) and PRDM16 (n = 2). Other likely disease-causing variants were detected in ACTC1, ACTN2, HCCS, LAMA4, MYH6, RBM20, TAFFAZIN and TTN. Patients with established molecular defects more often presented with arrhythmia, thromboembolic events and death, whereas the predominant symptoms in patients with no identified molecular defects were heart failure and the presence of late gadolinium enhancement. Conclusion: This study expands the genetic and clinical spectrum of childhood LVNC. Although the molecular aetiology of LVNC varies widely, the comprehensive testing of a wide panel of cardiomyopathy-related genes helped to identify underlying molecular defects in more than half of the children in the study group. The molecular spectrum in our cohort correlated with the occurrence of arrhythmia, death and a family history of cardiomyopathy. We confirmed that genetic testing is an integral part of the work-up and management LVNC in children.

Objectives: Despite the high prevalence of isolated systolic hypertension (ISH) among hypertensive adolescents, its clinical significance is not determined. In addition, it is hypothesized that ISH with normal central blood pressure (BP) in young patients is a benign phenomenon and was hence labeled spurious hypertension (sHTN).Methods: Using cardiac magnetic resonance we evaluated a group of 73 patients with suspected primary hypertension, aged 13-17 years (median: 16.9, interquartile range 15.8-17.4; 13 girls), in whom, based on 24-h ambulatory BP monitoring either ISH (n ¼ 30) or white-coat hypertension (WCH) (n ¼ 43) was diagnosed. Based on noninvasive central BP measurement 13 participants in the ISH group were classified as having sHTN and 17 were diagnosed with true hypertension.Results: Compared with WCH adolescents, ISH patients presented with higher indexed left ventricular mass index (LVMI) (P < 0.001), maximal left ventricular (LV) wall thickness (P < 0.001), LV concentricity (P ¼ 0.001) and more often had LV hypertrophy (47 vs. 14%, P ¼ 0.002). They had higher average pulse wave velocity (PWV) in the proximal aorta (P ¼ 0.016) and the whole thoracic aorta (P ¼ 0.008). In addition, we observed higher indexed LV stroke volume (P ¼ 0.025) in patients with ISH. The sHTN subgroup had significantly higher LVMI and aortic PWV, and more often had LV hypertrophy compared with the WCH group. The sHTN and true hypertension subgroups did not differ in terms of aortic PWV, LVMI or LV geometry. Conclusion:Compared with adolescents with WCH patients with ISH, including the sHTN subtype, have more pronounced markers of cardiac end-organ damage, higher aortic stiffness and stroke volume.