Dynamic adaptive changes in heart function first 10 days after birth in healthy term neonates

Area of Science:

• Neonatal physiology
• Cardiovascular adaptation
• Pediatric cardiology

Background:

• Understanding early neonatal cardiac adaptation is crucial for identifying potential issues.
• The transition from fetal to neonatal circulation involves significant hemodynamic changes.
• Limited data exists on serial cardiac function assessments in the first ten days of life.

Purpose of the Study:

• To investigate the temporal changes in heart function in healthy term neonates during the first ten days after birth.
• To assess left and right ventricular systolic function using advanced echocardiographic techniques.
• To explore the impact of heart rate on cardiac function parameters.

Main Methods:

• Prospective observational study of 50 healthy term neonates.
• Serial echocardiographic assessments including speckle tracking echocardiography (STE) and pulsed-wave tissue Doppler imaging (pwTDI) at days 1, 3, and 6-10 postpartum.
• Linear mixed effects models were used to analyze changes in cardiac function over time and the influence of heart rate.

Main Results:

• Left ventricular global longitudinal strain (GLS) decreased from day 1 to day 6-10.
• Right ventricular longitudinal strain, strain rate, and peak systolic velocity (s') increased significantly over the first ten days.
• Both ventricles showed increased systolic strain rate with increasing heart rate.

Conclusions:

• Neonatal left ventricular systolic function declines in the first few days post-birth, with stabilization not occurring by day three.
• Right ventricular systolic function improves progressively over the first ten days, with significant changes noted after day three.
• Evaluation of neonatal heart function requires consideration of the postnatal day due to distinct temporal adaptations in each ventricle.