Evaluation of Biventricular Diastolic Function in Preterm Infants in the First Week of Postnatal Life

Area of Science:

• Neonatal cardiology
• Pediatric echocardiography
• Preterm infant physiology

Background:

• Diastolic dysfunction is a key factor in respiratory issues for preterm infants.
• Understanding diastolic function during early postnatal transition is crucial but limited.
• Very low birth weight (VLBW) infants face unique cardiovascular challenges.

Purpose of the Study:

• To assess the changes in biventricular diastolic function over the first week of life in VLBW preterm infants.
• To investigate the relationship between diastolic function and hemodynamically significant patent ductus arteriosus (hsPDA).
• To explore the impact of other shunts like patent foramen ovale (PFO) on diastolic parameters.

Main Methods:

• Prospective observational study of 20 VLBW preterm infants (<32 weeks gestation or <1500g).
• Serial echocardiograms performed at 24, 48, 72 hours, and day 7.
• Measurements included TDI mitral/tricuspid inflow velocities, left atrial (LA) volume, cardiac output, and shunt characteristics.

Main Results:

• Diastolic function showed significant improvement, with mitral E/e' decreasing and lateral e' increasing by day 7.
• Infants with hsPDA exhibited higher mitral E/A ratios and elevated E/e' at day 7, indicating impaired relaxation.
• The hsPDA group also presented with larger indexed LA volumes.

Conclusions:

• VLBW preterm infants undergo rapid diastolic adaptation in the first postnatal week.
• hsPDA is associated with increased left atrial pressure and impaired diastolic relaxation.
• Early functional echocardiography can guide targeted neonatal care for diastolic dysfunction.