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Published on: January 27, 2023
[Reference ranges for M-mode echocardiographic measurements within seven days after birth in preterm infants]
1Department of Pediatrics, Peking University Third Hospital, Beijing 100191, China.
Insights
This study established M-mode echocardiography reference ranges for preterm infants, showing heart chamber dimensions and ventricular wall thickness correlate with gestational age and birth weight. These ranges aid in reliable assessment of preterm neonates within the first week of life.
Area of Science:
- Neonatal Cardiology
- Pediatric Echocardiography
- Perinatal Medicine
Background:
- Establishing normative echocardiographic data is crucial for assessing cardiac function in preterm infants.
- Existing reference ranges may not adequately account for variations in gestational age (GA) and birth weight (BW) in neonates.
- M-mode echocardiography provides essential measurements of cardiac structure and function.
Purpose of the Study:
- To establish reference ranges for M-mode echocardiography parameters in preterm infants within 7 days of birth.
- To analyze the correlation between echocardiographic measurements and gestational age (GA) and birth weight (BW).
- To provide reliable reference values for clinical assessment of preterm neonates.
Main Methods:
- Retrospective analysis of M-mode echocardiographic data from 489 preterm infants.
- Infants categorized by gestational age (GA) and birth weight (BW) into distinct groups.
- Statistical analysis (Kruskal-Wallis test) used to compare M-mode values and establish 95% confidence intervals (CI) and Z-score reference ranges.
Main Results:
- Interventricular septum thickness (IVSd), left ventricular posterior wall thickness (LVPWd), left atrial diameter (LAD), left ventricular end-diastolic diameter (LVED), left ventricular end-systolic diameter (LVES), right ventricular outflow tract (RVOT), and right ventricular end-diastolic diameter (RVED) all correlated significantly with GA and BW (P<0.01).
- Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) showed no significant correlation with GA or BW (P>0.05).
- Greater GA and BW were associated with larger heart chamber diameters and thicker ventricular walls within the first 7 days post-birth. LVEF and LVFS remained stable and high (95% CI: 67%-69% and 34%-36%, respectively).
Conclusions:
- Reference ranges for M-mode echocardiographic measurements (chamber diameters, septal and wall thickness) were successfully established for preterm infants aged 0-7 days, stratified by GA and BW.
- These GA- and BW-adjusted 95% CI and Z-score ranges offer a reliable tool for evaluating preterm neonates.
- The findings support the use of tailored reference ranges for accurate echocardiographic assessment in this vulnerable population.
Abstract:
Objective: To establish reference ranges for M-mode echocardiography in preterm infants within 7 days after birth based on different gestational age (GA) and birth weight. Methods: This retrospective study analyzed M-mode echocardiographic values of 489 premature infants, who were admitted to the neonatal intensive care unit of Department of Pediatrics, Peking University Third Hospital from March 2017 to February 2020. These infants were divided into four groups according to GA:<28 weeks, 28-31+6weeks, 32-33+6weeks and 34-36+6weeks; and five groups according to birth weight:<1 000 g, 1 000-1 499 g, 1 500-1 999 g, 2 000-2 499 g and ≥2 500 g. The M-mode values among groups were compared by independent sample K-W test, and based on which, the 95% confidence interval (CI) and the Z-value reference ranges were established. Results: The gestational age of these infants was 32.0 (24.0-36.7) weeks, and the birth weight was 1 700 (650-3 180) g. The interventricular septum end-diastolic thickness (IVSd), left ventricular posterior wall end-diastolic thickness (LVPWd), left atrial diameter (LAD), left ventricular end-diastolic diameter (LVED), left ventricular end-systolic diameter (LVES), right ventricular outflow tract (RVOT) and the right ventricular end-diastolic diameter (RVED), were all correlated with GA and birth weight (r = 0.209, 0.216, 0.430, 0.608, 0.495, 0.464, 0.447; r = 0.275, 0.288, 0.445, 0.609, 0.496, 0.499, 0.464;all P<0.01). While the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) had no correlation with GA or birth weight (all P<0.05). Within the first 7 days after birth, the greater the GA and birth weight, the greater the inner diameters of the heart chambers, and the thicker the ventricular wall. The LVEF and LVFS maintained a high and stable level within the first week of life (95%CI: 67%-69%, 34%-36%). Conclusions: According to different GA and birth weight, the reference ranges for chamber diameters, interventricular septal thickness and left ventricular wall thickness within 7 days were established. The 95% CI and Z score ranges for M-mode echocardiographic measurements established based on gestational age and birth weight can provide a reliable reference for preterm infants aged 0-7 days.
