Haycock Formula Research Articles

Echocardiographic nomograms of heart chambers and great arteries in peruvian children living at high altitude according to sex

Abstract Background Reference values in pediatric echocardiography are crucial for clinical decision making. The availability of nomograms may support interpretation of the echocardiographic findings and clinical diagnosis. Cardiac chamber dimensions vary according to body size, age, sex, and to some extent, geographic background in children. Purpose The aim of this study was to establish two-dimensional and M-mode echocardiographic reference values for cardiac chambers, outflow tracts and great vessels for school children living at high altitude, differentiated between male and female. Methods This is a post-hoc analysis from a cluster randomized cross-sectional survey of rheumatic heart disease in school children in Arequipa, Peru. Children with normal echocardiographic screening were included for this sub-study. The echocardiograms were acquired with a portable machine and the images were analyzed centrally with a standardized methodology. Body surface area (BSA) was used as an independent variable to predict the mean values of echocardiographic measurements for both male and female groups. Reference values are presented with z-scores and nomograms based on the sex. Results A total of 985 students from ages 5-16 years were included. The Haycock formula provided the best fit and was used when presenting data as predicted values for a given BSA. The z-score and nomograms for all essential dimensional measures of cardiac chambers and great vessel, as well as functional surrogates are presented based on sex. Left ventricular chamber and mass are presented in Figure 1 and right ventricular dimensions are presented in Figure 2. Conclusions Normal reference values and nomograms of cardiac chamber, outflow tracts and great arteries in healthy school children living at high altitude based on sex were reported. These data partly cover a gap in existing pediatric echocardiographic nomograms. Left ventricular chamber and mass Right ventricular dimensions

Computed tomography-derived normative values and z-scores of the pulmonary valve annulus and sino-tubular junction in the pediatric population

BackgroundAccurate assessment of the pulmonary valve can dictate clinical management of patients with right ventricular outflow tract (RVOT) anomalies. Comparisons with available normal reference values are essential for accurate evaluation. The aim of the study was to generate normative data for the pulmonary valve annulus and sino-tubular (ST) junction using CT measurements derived from a heterogeneous pediatric population and create z-scores useful for clinical practice. MethodsPatients without heart disease who underwent cardiac CT between April 2014 and February 2021 ​at Children's Hospital Colorado were included. Minimum and maximum diameter (mm) and cross-sectional area (mm2) for the pulmonary valve annulus and ST junction were measured. Previously validated models were used to normalize the measurements and calculate z-scores. Each measurement was plotted against BSA, and z-score distributions were used as reference lines. ResultsThree-hundred-sixty-seven healthy patients with a mean age of 8.8 years (1–21), 56% male, and BSA of 1.1 ​m2 (0.4–2.1) were analyzed. The Haycock formula was used to present data as predicted values for a given BSA and within equations relating each measurement to BSA. Predicted values and z-score boundaries for all measurements are graphically re-presented. ConclusionsCT-derived normative data for the pulmonary valve annulus and ST junction is reported from a heterogenous cohort of healthy children.

Computed Tomography-Derived Normative Values of Right Ventricular Outflow Tract Structures in the Pediatric Population.

Recent advances in available percutaneous device technology require accurate measurements and quantification of relationships between right ventricular outflow tract (RVOT) structures in children with and without congenital heart disease to determine device suitability. To date, no population study has described normal reference ranges of these measurements by computed tomography (CT). We aimed to establish normative values for four CT-derived measurements between RVOT structures from a heterogeneous population without heart disease and develop z scores useful for clinical practice. Patients without heart disease who underwent cardiac CT between April 2014 and February 2021 at Children's Hospital Colorado were included. Distance between the right ventricular (RV) apex to pulmonary valve (PV), PV to pulmonary trunk bifurcation, and bifurcation to the right and left pulmonary artery was measured. Previously validated models were used to normalize the measurements and calculate Z scores. Each measurement was plotted against BSA and Z scores distributions were used as reference lines. Three-hundred and sixty-four healthy patients with a mean age of 8.8years (range 1-21), 58% male, and BSA of 1m2 (range 0.4-2.1) were analyzed. The Haycock formula was used to present data as predicted values for a given BSA and within equations relating each measurement to BSA. Predicted values and Z-score boundaries for all measurements are presented.We report CT-derived normative data for four measurements between RVOT structures from a heterogeneous cohort of healthy children.Knowledge of this normative data will be useful in both determining device fit and customizing future devices to accommodate the diverse pediatric size range.

Echocardiographic nomograms and Z-scores for term Indian neonates.

The availability of nomograms is crucial for the correct interpretation of pediatric and neonatal echocardiograms. Echocardiographic Z-score applications/websites use Western nomograms as reference, which may not be an appropriate standard for gauging Indian neonates. Currently available Indian pediatric nomograms either have not included neonates or have not been specifically designed for neonates. This gross underrepresentation of neonates renders available nomograms unreliable for use as standards for comparison. The objective of this study was to collect normative data for the measurement of various cardiac structures using M-Mode and two-dimensional (2D) echo in healthy Indian neonates and to derive Z-scores for each measured parameter. Echocardiograms were performed on healthy term neonates (within first 5 days of life). Birth weight and length were recorded, and body surface area was calculated using Haycock's formula. Twenty M-mode and 2D-echo parameters were measured (including left ventricular dimensions, atrioventricular valves, and semilunar valves' annuli sizes, pulmonary artery and branches, aortic root, and arch). We studied 142 neonates (73 males) with a mean age of 1.83 ± 1.12 days and mean birth weight of 2.89 ± 0.39 Kg. Regression equations with linear, logarithmic, exponential and square root models were tested to select the best model of fit for the relationship between birth weight and each echocardiographic parameter. Scatter plots and nomogram charts with Z-scores were prepared for each echocardiographic parameter. Our study provides nomograms with Z-scores for term Indian neonates weighing between 2 kg and 4 kg at birth, within first 5 days of life, for a set of echocardiographic parameters that are frequently used in clinical practice. This nomogram has poor predictability for babies at extremes of birth weight. There is a need for further indigenous studies to include neonates at extremes of weight, both term, and preterm.

Reference values (Z-score) of inlet and trabecular portion diameters of the right ventricle: First description in Spanish healthy children

Right ventricle (RV) measurements are crucial for certain congenital heart diseases and various cardiovascular conditions. Echocardiographic RV diameters are especially useful for its assessment. Paediatric echocardiographic data standardisation in normal subjects is complex, scarce, and heterogeneous. The aim of this study was to establish reliable and reproducible echocardiographic reference values (Z-score) of RV diameters in a healthy Spanish paediatric cohort. A multicentre study was conducted on 661 healthy subjects (age range 0-18 years, 43.5% female). Several regression models were tested to examine the relationship between RV diameters and biometric variables. Heteroscedasticity and residual associations (Shapiro-Wilk and Breusch-Pagan tests) and confounding factors (gender, age, inter/intraobserver agreement) were considered for an unbiased standardisation. Structured Z-scores were computed for each RV diameter. Predicted mean value for each diameter was determined according to age, weight, height, and different body surface area. The Haycock formula provided the best fit for basal, midcavity, and longitudinal diameters (R2 0.81; 0.82; 0.9). Confounders were not significant, and therefore not included in final models (inter/intraobserver agreement > 0.9). This study reports reference values for echocardiographic RV diameters from a Spanish healthy paediatric cohort using a rigorous statistical design. These Z-scores partly cover a gap in current paediatric cardiology and represent a relevant diagnostic tool for clinical practice, as well as a useful guide to decision making at any paediatric stage.

Reference values (Z-score) of inlet and trabecular portion diameters of the right ventricle: First description in Spanish healthy children

Introduction and objectivesRight ventricle (RV) measurements are crucial for certain congenital heart diseases and various cardiovascular conditions. Echocardiographic RV diameters are especially useful for its assessment. Paediatric echocardiographic data standardisation in normal subjects is complex, scarce, and heterogeneous. The aim of this study was to establish reliable and reproducible echocardiographic reference values (Z-score) of RV diameters in a healthy Spanish paediatric cohort. MethodsA multicentre study was conducted on 661 healthy subjects (age range 0–18 years, 43.5% female). Several regression models were tested to examine the relationship between RV diameters and biometric variables. Heteroscedasticity and residual associations (Shapiro–Wilk and Breusch–Pagan tests) and confounding factors (gender, age, inter/intraobserver agreement) were considered for an unbiased standardisation. ResultsStructured Z-scores were computed for each RV diameter. Predicted mean value for each diameter was determined according to age, weight, height, and different body surface area. The Haycock formula provided the best fit for basal, midcavity, and longitudinal diameters (R2 0.81, 0.82, 0.9). Confounders were not significant, and therefore not included in final models (inter/intraobserver agreement > 0.9). ConclusionsThis study reports reference values for echocardiographic RV diameters from a Spanish healthy paediatric cohort using a rigorous statistical design. These Z-scores partly cover a gap in current paediatric cardiology and represent a relevant diagnostic tool for clinical practice, as well as a useful guide to decision making at any paediatric stage.

Six commonly used empirical body surface area formulas disagreed in young children undergoing corrective heart surgery.

Formulas for empirical body surface area (BSA), which is used to estimate body size and standardise physiological parameters, may disagree in children. We compared six commonly used BSA formulas-Du Bois, Boyd, Costeff, Haycock, Meban and Mosteller-in a surgical cohort. This retrospective single-centre cohort study comprised 68 children who had corrective heart surgery at Skåne University Children's Hospital, Lund, Sweden, from February 2010 to March 2017. The children (51% female) underwent surgery at a mean weight of 7.0 kilograms (range 2.7-14.1kg) and a mean age 11months (range 0-43months). All the BSA formulas showed good correlation with mean BSA, but there were considerable variations between them. Mosteller's formula was exactly the same as the mean BSA (bias 0.000). The Du Bois and Boyd formulas had the largest mean BSA deviations (bias -0.012 and 0.015). Costeff's formula showed good agreement with mean BSA, Haycock's formula showed minimal overestimation and Meban's formula demonstrated a systemic error in older children. Commonly used BSA formulas did not agree in young children undergoing heart surgery, but they were all close to the overall mean of the six formulas, with the Mosteller formula producing the same value.

P2735Ventricular function in a large cohort of healthy, term newborns assessed by tissue doppler imaging and speckle tracking echocardiography; establishment of normal values and z-scores

Abstract Background There is a paucity of published data presenting reference values for ventricular function in newborns. Purpose This study was conducted to establish echocardiographic normal data and z-scores for ventricular functional parameters in newborns assessed by Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE). Methods We included healthy, term newborns from a prospective, population-based study of newborns, who had a comprehensive, systematic echocardiographic (TTE) examination performed within 14 days of birth. Only newborns without any signs of structural or functional cardiac abnormalities were included. Measurements were obtained according to guidelines. Body surface area (BSA) was calculated using the Haycock formula. Z-score models according to birthweight and BSA at time of TTE were developed for TDI and STE parameters. Results Four hundred newborns (53% male) with gestational age of (median (IQR)) 40.3 (39.4, 41.1) weeks were included. Age, weight, and BSA at TTE were (mean±SD) 11±3 days, 3.7±0.5 kg, and 0.23±0.02m2, resp. Ejection fraction was 67±4%. TDI and STE measurements of ventricular function are presented as mean±SD (Table). Global longitudinal strain was calculated as the average of all left ventricular segmental strain values from apical 4-, 2-, and 3-chamber views. Results for selected parameters according to BSA are illustrated (Figure). TDI and STE of ventricular function Parameter View and modality Value Unit Mitral annulus septal wall e' Apical 4-chamber Tissue Doppler 5.7±0.8 cm/s Mitral annulus septal wall a' Apical 4-chamber Tissue Doppler 5.9±1.0 cm/s Mitral annulus septal wall s' Apical 4-chamber Tissue Doppler 4.6±0.6 cm/s Mitral annulus lateral wall e' Apical 4-chamber Tissue Doppler 6.9±1.0 cm/s Mitral annulus lateral wall a' Apical 4-chamber Tissue Doppler 6.0±1.1 cm/s Mitral annulus lateral wall s' Apical 4-chamber Tissue Doppler 4.8±0.6 cm/s Left ventricular longitudinal strain, 4-chamber Apical 4-chamber 2D 19±2 % Left ventricular longitudinal strain, 2-chamber Apical 2-chamber 2D 20±2 % Left ventricular longitudinal strain, 3-chamber Apical 3-chamber 2D 19±2 % Left ventricular global strain 19±2 % Right ventricular longitudinal strain, free wall Apical 4-chamber 2D 23±4 % Percentile charts Conclusion Normal data for TDI and STE assessment of ventricular function in 400 healthy, term newborns ispresented. An online z-score calculator will be available. Normal data is necessary for the evaluation of pathological changes, and these results contribute substantially to a field where available data is limited. Acknowledgement/Funding Danish Heart Association, Danish Children's Heart Foundation, Candy's Found., Toyota Found., Herlev-Gentofte Hospital Research Found., Gangsted Found.

Aortic root dilatation in patients with mucopolysaccharidoses and the impact of enzyme replacement therapy.

Mucopolysaccharidoses (MPS) are disorders characterized by impaired glycosaminoglycan (GAG) catabolism as a consequence of a deficiency or the absence of lysosomal enzymes directly involved in their degradation. Multiple organ systems are involved in MPS, including the cardiovascular system. Recently, aortic root dilatation (ARD) has been described in these patients. Thus, we reviewed aortic root diameter measurements in 69 MPS patients from a single center from 2000 to 2016. Aortic root diameter z scores were calculated based on data published by Colan et al. according to the body surface area (BSA) determined using the Haycock formula. The overall incidence of ARD in MPS patients was 39.1%. Higher mean z scores were present in patients with MPS IVA and VI when compared to MPS I and II. Aortic root z scores were higher in older MPS IVA patients, which may suggest a progressive ARD change in this MPS type. No significant differences were found before and after enzyme replacement therapy (ERT) in 11 patients with available data (2 with MPS I; 4 with MPS II; 2 with MPS IVA, and 3 with MPS VI). This work provides further evidence that ARD is common in different types of MPS, being especially evident in MPS IVA, but with a significant occurrence also in MPS VI.

Nomograms for echocardiographic right ventricular sub-costal view dimensions in healthy Caucasian children: A new approach to measure the right ventricle

BackgroundThe sub-costal examination of the heart is part of routine examination in pediatric echocardiography, and has the advantage to visualize also the infundibulum part of the right ventricle (RV). Despite this fact, currently nomograms for sub-costal RV dimensions are lacking. MethodsWe prospectively studied healthy Caucasian Italian children by two-dimensional echocardiography. Measurements included: sub-costal end diastolic basal-apical and latero-lateral diameters, end diastolic and end systolic area, 4 chamber end diastolic and end systolic area and length, end diastolic basal (RV1) and mid-cavity (RV2) diameters. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Structured Z scores were then computed. Agreement of RV diameters and areas in subcostal view and 4-chamber view were investigated. Results732 subjects (age 0 days-17 years; 48% female; BSA 0.12-2.12 m2) were studied. The Haycock formula was used when presenting data as predicted values (mean ± 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. The predicted values and Z-score boundaries for all measurements are presented. Excellent correlations were found among two-dimensional diameters and area calculated in sub-costal view with those evaluated in 4-chamber view. ConclusionsWe report echocardiographic nomograms for RV diameters and areas measured in the sub-costal view. Our data may implement normative data for 2D echocardiography evaluation of the RV in children.

Nomograms for two-dimensional echocardiography derived valvular and arterial dimensions in Caucasian children

BackgroundDespite recent advances, current pediatric echocardiographic nomograms for valvular and arterial dimensions remain limited. MethodsWe prospectively studied healthy Caucasian Italian children by two-dimensional (2D) echocardiography. Echocardiographic measurements for 18 valvular and arterial dimensions were performed and models were generated testing for linear, logarithmic, exponential, and square root relationships. Heteroscedasticity was accounted for by White or Breusch–Pagan test. Age, weight, height, heart rate, and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Structured Z-scores were then computed. ResultsIn all, 1151 subjects (age 0 days to 17 years; 45% females; BSA 0.12–2.12m2) were studied. The Haycock formula was used when presenting data as predicted values (mean±2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. The predicted values and Z-score boundaries for all measurements are presented. ConclusionsWe report echocardiographic nomograms for valvular and arterial dimensions derived from a large population of children. Integration of these data with those of previous reports would allow for a comprehensive coverage of pediatric 2D echocardiographic nomograms for measurement of 2D cardiac structures.

Echocardiographic Nomograms for Chamber Diameters and Areas in Caucasian Children

Although a quantitative evaluation of cardiac chamber dimensions in pediatric echocardiography is often important, nomograms for these structures are limited. The aim of this study was to establish reliable echocardiographic nomograms of cardiac chamber diameters and areas in a wide population of children. A total of 1,091 Caucasian Italian healthy children (age range, 0 days to 17 years; 44.8% female) with body surface areas (BSAs) ranging from 0.12 to 1.8m(2) were prospectively enrolled. Twenty-two two-dimensional and M-mode measurements of atrial and ventricular chamber diameters and areas were performed. Models using linear, logarithmic, exponential, and square-root relationships were tested. Heteroscedasticity was tested by the White test and the Breusch-Pagan test. Age, weight, height, and BSA, calculated by the Haycock formula, were used as the independent variables in different analyses to predict the mean value of each echocardiographic measurement. The influence of various confounders, including gender, type of delivery, prematurity, and interobserver variability, was also evaluated. Structured Z scores were then computed. The Haycock formula provided the best fit and was used when presenting data as predicted values (mean ± 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. Confounders were not included in the final models, because they did not show significant effects for most of the measurements. Echocardiographic reference values are presented for chamber area and diameters, derived from a large population of healthy children. These data partly cover a gap in actual pediatric echocardiographic nomograms. Further studies are required to reinforce these data, as well as to evaluate other parameters and ethnicities.

Echocardiographic Nomograms for Ventricular, Valvular and Arterial Dimensions in Caucasian Children with a Special Focus on Neonates, Infants and Toddlers

A quantitative echocardiographic assessment is often essential for the management of congenital heart disease, especially in the first months of life. Despite this, pediatric echocardiographic nomograms are limited and heterogeneous, particularly for neonates and infants. The aim of this study was to establish reliable echocardiographic nomograms in a broad population of healthy Caucasian children. Two-dimensional and M-mode measurements of 22 cardiovascular structures were performed.Models using linear, logarithmic, exponential, and square root relationships were tested. Heteroscedasticity was tested using the White and Breusch-Pagan tests. Age, weight, height, and body surface area(BSA; calculated using seven different formulas) were used as the independent variables in different analyses to predict the mean value of each echocardiographic measurement. Structured Z scores were then computed. A total of 445 consecutive Caucasian Italian healthy subjects (age range, 0 days to 36 months; 49%female subjects) with BSAs ranging from 0.12 to 0.67 m(2) were prospectively enrolled. The calculation of BSA using the Haycock formula provided the best results, while other formulas either underestimated (DuBois, Mosteller, Dreyer, and Meban) or overestimated (Boyd and Gehan) BSA. The Haycock formula has been used when presenting data as predicted values (mean ± 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. For all the measurements, there was no significant intraobserver or interobserver variability. The investigators report new, reliable echocardiographic Z scores derived from a large population of Caucasian neonates, infants, and toddlers calculated using a rigorous statistical design. These nomograms represent a valid diagnostic tool for echocardiographic quantification in this age group.

Glomerular filtration rate in prospective living kidney donors

Measurements of glomerular filtration rate (GFR) are frequently interpreted assuming a linear variation with age. Nonlinear relationships may give a better representation of the changes associated with normal ageing. This was a retrospective study of 904 subjects (468 women, 436 men; age range 18-84 years) undergoing assessment as prospective living kidney donors. GFR was evaluated from (51)Cr-EDTA plasma clearance using blood samples taken at 2, 3 and 4 h. The slope-intercept GFR was corrected for body surface area (BSA) using the Haycock formula and for the fast exponential using the Brochner-Mortensen equation. The relationship between age, gender and GFR was examined using best-fit curve analysis. Nonlinear relationships with age were explored using fractional polynomials. There was no gender difference in BSA-corrected GFR over five decades of age (P = 0.40). However, female donors with a body mass index >30 kg/m(2) had a statistically significantly lower GFR than nonobese women (P < 0.01). The best-fit relationship between age and GFR was nonlinear and described using a fractional polynomial model of degree 1 (GFR = 103.9-0.0061 × Age(2) mL/min/1.73 m(2)) with a root mean standard error of 12.9 mL/min/1.73 m(2). The residual variance for this model was significantly smaller than for the best-fit linear model (P = 0.006). GFR measurements in prospective living kidney donors are best corrected for age using a nonlinear relationship.

Reference data for 51Cr-EDTA measurements of the glomerular filtration rate derived from live kidney donors

51Cr-Ethylenediaminetetraacetic acid (51Cr-EDTA) is widely used to measure the glomerular filtration rate (GFR) for the assessment of renal function. The aims of this study were to assess the dependence of GFR on age and gender and to produce reference data for the interpretation of 51Cr-EDTA GFR measurements in adults. This was a retrospective study of 428 subjects (218 females, 210 males; age range, 19-72 years) undergoing assessment as live kidney donors. GFR was evaluated from 51Cr-EDTA plasma clearance using blood samples taken at 2, 3 and 4 h. The slope-intercept GFR was corrected for body surface area using the Haycock formula and for the fast exponential using the Brochner-Mortensen equation. The data were analysed for the dependence on age and gender using multivariate regression analysis. Precision was evaluated from duplicate measurements in 22 subjects. For 187 subjects, aged 19-40 years, the dependence of GFR on age was not statistically significant (P = 0.51). The mean GFR was 103.4 ml x min(-1) x (1.73 m2)(-1) with a root mean standard error (RMSE) of 15.5 ml x min(-1) x (1.73 m2)(-1). GFR was 1.3 ml x min(-1) x (1.73 m2)(-1) higher in men than in women, although the difference was not significant (P = 0.56). In 241 subjects, aged 40-73 years, GFR decreased by 0.91 ml x min(-1) x (1.73 m2)(-1) per year [standard error, 0.06 ml x min(-1) x (1.73 m2)(-1) per year] with an RMSE of 13.6 ml x min(-1) x (1.73 m2)(-1). Over both age groups GFR was 0.4 ml x min(-1) x (1.73 m2)(-1) higher in men than in women [P=0.80; 95% confidence interval, -2.4 to +3.1 ml x min(-1) x (1.73 m2)(-1)]. For the 22 subjects with duplicate measurements, the root mean square coefficient of variation was 10.4%. A model for the decline of GFR with age was produced in which GFR remains constant at 103.4 ml x min(-1) x (1.73 m2)(-1) until the age of 40 years and then declines at a rate of 9.1 ml x min(-1) x (1.73 m2)(-1) per decade. The data can be used to report the results of adult 51Cr-EDTA GFR investigations.

1351 MEASUREMENT OF BODY SURFACE AREA (BSA) IN PREMATURE INFANTS (PT)

BSA is an important factor in caloric expenditure, fluid and drug management and assessment of GFR. Formulas designed for adults, children and infants have not been validated in PT. We performed 91 measurements of BSA in 70 PT of 3 gestational age (GA) groups (max I measurement per wk, per infant), using a geometric method (considering the body as a series of cylinders and the head as a sphere) that has been derived for older infants, children and adults (Haycock, et al., J. Ped. 93:62, 1978). We compared the geometria values to those obtained by 4 length-weight formulas based on BSA (m2)=a LbWc, where L is the body length (cm), W is the weight (kg) and a/b/c are respectively: for Haycock's: .024265/.3964/.5378, for Dubois1: .007184/.7258/.425 for Gehan's: .02350/.42246/.51456 and for Boyd's: .017827/.500/.4838. The mean differences (Geometric- a LbWc ± SE) between BSA obtained by geometric measurement and by each formula are shown:The mean BSA obtained by Gehan's and Boyd's formulas overestimate the measured BSA by 7% or more, whereas the 2 other formulas give an error less than 3%. Therefore, Dubois' or Haycock's formula may be used in PT. Since Dubois' substantially overestimates BSA in larger infants and children, Haycock's formula is recommended for use in the general pediatric population, including PT and very low birth weight infants.