Cardiorespiratory phase synchronization maturational trajectory: biomarker of autonomic nervous system development in...

Cardiorespiratory coupling (cardiovascular-respiratory interactions) is a marker of autonomic nervous system function and maturation. We hypothesize that differences in autonomic maturation are associated with disparate outcomes of premature infants.

We collected continuous bedside cardiorespiratory data from birth to 40 weeks post-menstrual age (PMA) for 191 preterm infants born between 23-0/7 weeks to 28-6/7 weeks of gestation. Using the respiratory and ECG wave forms, we calculated cardiorespiratory phase synchronization (CRPS) as a measure of cardiorespiratory coupling. Using linear mixed effects modeling, we studied the trajectory of CRPS as a function of PMA and chronological age (CA) and any difference between groups separated by discharge status, respiratory outcome and neurological outcomes at the 40th week PMA, and different gestational ages.

CRPS showed a decline reaching a nadir at approximately 3 weeks of age followed by a gradual increase toward term. The infants born at later GA showed higher values and steeper increases than infants of lower GA. Contrary to our hypothesis, the trajectory of the increase was similar regardless of outcome assessed.

Autonomic maturation following preterm birth shows a fixed predictable pattern that appears to be independent of respiratory or neurologic outcomes or clinicians' assessment of readiness for discharge.

Cardiorespiratory phase synchronization (CRPS) trajectories, a marker of autonomic nervous system functio is provided for 175 extremely preterm infants across post-menstrual age (PMA) and chronological age (CA). CRPS initially declines but subsequently increases with advancing PMA and CA, irrespective of discharge status and respiratory and neurological outcomes at 40 weeks PMA. At all CAs after the initial decrease, CRPS was higher for infants born at 27-28 weeks compared to those born earlier.