Echocardiographic reference z scores of right ventricular dimension and systolic function of children aged 5-12 years.

BACKGROUND: Reference values for right ventricular dimension and systolic function in Nigerian children are scarce despite their high burden of right ventricular abnormalities. Reference values from other countries may not be suitable for use in Nigerian children because of possible racial variations in cardiac size. PURPOSE: To develop reference values for right ventricular dimension and systolic function in healthy Nigerian children aged 5-12 years. METHODS: This descriptive cross-sectional study conducted between July and November 2019 included 480 healthy boys and girls aged 5-12 years. The participants were randomly selected from 6 primary schools in the Ikeja Local Government area of Lagos State and their weights and heights measured. Body mass index and body surface area were calculated. Echocardiography was performed at rest in the left lateral position. RESULTS: The right ventricular end-diastolic basal diameter (RVD1), right ventricular end-diastolic mid-cavity diameter (RVD2), and right ventricular end-diastolic length (RVD3) were obtained. The right ventricular end-diastolic basal diameter (RVD1), right ventricular end-diastolic mid-cavity diameter (RVD2), and right ventricular end-diastolic length (RVD3) were obtained, as well as tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler-derived right ventricular systolic excursion velocity (S'). The overall mean±standard deviation (SD) values for RVD1, RVD2, RVD3, TAPSE, and S' were 32.95±4.2, 25.86±3.5, 54.57±7.5, 20.11±2.3, and 18.24±2.2, respectively. Age- and sex-specific mean and SD values of the same cardiac indices were determined. Z score charts and the mean± 2SD right ventricular dimensions and systolic function were generated. All right ventricular dimensions were positively correlated with weight, height, body surface area, and body mass index. Only height correlated consistently with TAPSE and S'. CONCLUSION: The observed mean right ventricular dimension indices differed from those derived elsewhere, suggesting that values from other countries may be inappropriate for Nigerian children. These reference values are applicable in daily clinical practice.

Reference values and equations for the 6-minute walk distance of Nigerian children aged 6-11 years: A cross-sectional study.

BACKGROUND: The 6-minute walk test (6MWT), a simple, reliable, and valid test that uses the distance walked in 6 minute walk distance (6MWD) to quantify functional capacity, is widely used in the management of chronic disorders. However, the absence of reference standards from sub-Saharan African, including Nigerian, school-aged children limits its utility in this age group. OBJECTIVES: To develop normative values and equations for the 6MWD of school-aged Nigerian children. METHODS: In a cross-sectional study, healthy children aged 6-11 years in Lagos, Nigeria, completed the 6MWT on 20-m-long straight outdoor courses in their schools. The primary outcome was the 6MWD in meters while potential predictors included demographic (age, sex), anthropometric (height, weight, chest circumference, leg length) and physiologic variables (pre-walk, immediate post-walk, and fifth min-post-walk heart rate [HR], oxygen saturation [SpO2 ], systolic blood pressure [SBP], diastolic blood pressure [DBP], and rating of perceived exertion [RPE]; and the difference between pre-walk and post-walk HR [∆HR], SpO2 [∆SpO2 ], SBP [∆SBP], DBP [∆DBP], and RPE [∆RPE]). RESULTS: Overall, 627 pupils (52.1% girls) walked 504.6 ± 66.6 m (95% CI: 499.4, 509.8; range: 326.6-673.0 m); 16 m longer in boys (p = 0.002). A stepwise linear regression model yielded: 6MWD (m) = 347.9 + 14(Ageyears ) + 1.6 (∆HRbeats/min ) + 17.6(Sexmale=1, female=0 ) + 1.2(∆SBPmmHg ); R2 = 0.25. Previously published reference equations mostly over-estimated Nigerian children's 6MWD. CONCLUSION: These reference standards add to the global normative data on pediatric 6MWT and may be useful for the functional evaluation of Nigerian school-aged children with chronic childhood disorders.

Comparative Effectiveness of a Six-Week Treatment Course of Vitamin D2 and D3 in Children With Sickle Cell Anemia in Steady State With Hypovitaminosis D: A Randomized Clinical Trial.

BACKGROUND: Correction of vitamin D deficiency through administration of either vitamin D2 or D3 has been shown to reduce chronic bone pains and frequency of acute bone pains, increase bone density as well as improve growth stature in children with sickle cell anemia (SCA). Findings vary on the effectiveness of the two forms of the vitamin. The current study was carried out to compare the effectiveness of a 6-week treatment course of vitamin D2 and D3 in the correction of hypovitaminosis D (vitamin D insufficiency and deficiency) as well as evaluate treatment response to derangement of serum calcium and alkaline phosphatase (ALP) in children with SCA in steady state. METHODS: The study was a randomized, double-blind clinical trial of 174 children with SCA aged 1 - 18 years. Subjects with hypovitaminosis D (baseline serum 25-hydroxyvitamin D (25(OH)D) below 75 nmol/L) were randomized into two treatment arms. Each arm treated either of the two forms of vitamin D had a once weekly dose of 50,000 IU for a period of 6 weeks. RESULTS: Median rise in serum 25(OH)D after 6 weeks of oral vitamin D2 or D3 was similar between the two groups (median rise in 25(OH)D of 17.8 nmol/L in D2, 15.3 nmol/L in D3 groups). Also, there was no significant difference in the proportion of subjects that improved in their vitamin D status in both treatment arms (P = 0.409). Treatment was significantly associated with increase in proportion of subjects with normal serum calcium (P ≤ 0.001) and decrease in proportion of subjects with elevated serum ALP (P ≤ 0.001). CONCLUSION: Once weekly dose (50,000 IU) of either vitamin D supplement has equal effectiveness in correction of hypovitaminosis D. However, vitamin D3 may be cost-effective because it is cheaper.

The burden of rheumatic heart disease among children in Lagos: how are we fairing?

INTRODUCTION: Rheumatic heart disease still remains a cause of morbidity and mortality in low and middle income countries, despite its eradication in developed societies. The study aimed to document the features of children with rheumatic heart disease using clinical evaluation and echocardiography and compare it with reports from other part of the country. METHODS: A review of a prospectively collected data of patients with rheumatic heart disease who had echocardiography done from April 2007-Dec 2016. Information obtained from patients include age, sex, clinical indication for echocardiography, echocardiographic characterization of the valvular lesions and associated complications. RESULTS: A total of 324,676 patients were seen at the Paediatric unit of LASUTH from 2007 to 2016, out of which 36 had Rheumatic heart disease. This translates to a prevalence of 1.1 per 10,000 patients who presented at the study site during the study period. The prevalence of RHD amongst all the patients with structural heart disease was 2.6%. The mean age of patients was 9.12 ± 2.75 years with a male to female ratio of 1.6: 1. The most common valve affected was mitral valve. Heart failure was the most common mode of presentation found in 91.6%. Other complications were pulmonary hypertension and pericardial effusion. CONCLUSION: Rheumatic heart disease is still prevalent among children in Lagos although the prevalence is reducing. Heartfailure is the commonest mode of presentation and complication in them.

Pattern of Cerebral Blood Flow Velocity Using Transcranial Doppler Ultrasonography in Children with Sickle Cell Disorder in Lagos State, Nigeria.

Cerebrovascular accident (CVA) is a common, devastating neurological complication of sickle cell disorder (SCD) with a high recurrent and mortality rate. The Stroke Prevention Trial in Sickle Cell Anaemia study (STOP) recommends routine screening with transcranial Doppler ultrasonography in children aged two to sixteen years with SCD. The present study assessed cerebral blood flow velocities of children with SCD in accordance with the recommendation of routine screening by the STOP study. METHODS: Transcranial Doppler ultrasonography was done for children with SCD that attended Sickle Cell Foundation, Nigeria between July and November 2015. RESULTS: In all, 388 subjects were screened within the study period (360 HbSS and 28 HbSC). The prevalence of abnormal Time-Averaged Maximum Mean Velocity (TAMMV) of at least 200 cm/second was 10.8%: this was seen solely in HbSS subjects. The mean Time-averaged mean of the maximum (TAMM) velocity were 163±25 cm/sec, 162±30 cm/sec and 150±30 cm/sec for children less than five years, five to ten years and eleven to sixteen years respectively. CONCLUSION: The prevalence of abnormal TAMM velocity in children with HbSS is 10.8%. Identification of subjects at risk helped in primary CVA prevention by prompt therapy institution.