Altered early left ventricular diastolic cardiac function in the premature infant

Area of Science:

• Neonatal cardiology
• Pediatric cardiovascular research
• Infant cardiac physiology

Background:

• Diastolic ventricular function is crucial for adequate cardiac output.
• Understanding developmental changes in diastolic function is essential for identifying neonatal cardiac issues.
• Premature infants may experience unique physiological challenges affecting heart function.

Purpose of the Study:

• To assess and compare diastolic ventricular function in premature and term infants during the early neonatal period.
• To investigate the relationship between gestational age and diastolic function in neonates.
• To evaluate the changes in diastolic function over the first week of life in premature infants.

Main Methods:

• Utilized M-mode echocardiography to derive instantaneous rates of change in left ventricular (LV) cavity dimensions.
• Measured maximal velocity of LV cavity lengthening in 31 premature and 10 term infants within 72 hours of birth.
• Analyzed normalized indices of diastolic function and serial changes in 8 premature infants over 7 days.

Main Results:

• Maximal velocity of LV lengthening was significantly lower in premature infants (38 mm/s) than in term infants (88 mm/s).
• This velocity increased with gestational age (r = 0.87), with normalized indices also lower in more immature infants.
• In premature infants, the index of maximal velocity of lengthening divided by stroke dimension improved from 12.9 s-1 at 1 day to 16.5 s-1 at 7 days.

Conclusions:

• Premature infants exhibit depressed early diastolic ventricular function.
• Diastolic function shows improvement with increasing maturity and postnatal age in neonates.
• Echocardiographic assessment of diastolic function is valuable for evaluating neonatal cardiac health.