Echocardiographic nomograms in children living at high altitude according to sex.

Aims: This study aimed to establish 2D and M-mode echocardiographic reference values for cardiac chambers, outflow tracts, and great vessels for school children living at high altitudes, differentiated between males and females.

Methods and results: This post hoc analysis included children with normal echocardiography from a cluster randomized cross-sectional survey of rheumatic heart disease among school children in Peru. The echocardiograms were acquired with a portable machine and the images were analysed 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 on z-scores and nomograms based on sex. Propensity score matching was used to compare sexes. A total of 985 students aged 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 parameters of cardiac chambers, great vessels, and functional surrogates are presented based on sex. The majority of the parameters were significantly different per sex after propensity score matching.

Conclusion: Normal reference values and nomograms of cardiac chambers, outflow tracts, and great arteries in healthy school children living at high altitudes based on sex were reported. These data partly addressed the existing gaps in paediatric echocardiographic nomograms.