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
Bibliographic record
Abstract
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.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".