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
Authors: Sillesen A S , Voegg O , Raja A A , Pihl C , Dannesbo S , Davidsen A S , Lind L , Slorach C , Somerset E , Fan C P S , Manlhiot C , Vejlstrup N , Iversen K , Bundgaard H , Mertens L 
Published: October 2019

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.