Heart Rate Variability in Preterm Brain-Injured and Very-Low-Birth-Weight Infants

Abstract

Heart rate variability (HRV) reflects the complex interplay of the sympathetic and parasympathetic innervation of the heart. Developmental maturation of the fetus and newborn results in predictable alterations in the neural cardiac control of heart rate. Furthermore, patterns of HRV are closely correlated to clinical outcome in several pathologic situations. The first aim of this study was to characterize the maturational patterns of HRV in a group of developmentally at-risk newborns (those with severe hemorrhagic or ischemic brain injury and extremely immature, low-birth-weight infants). Secondly, we sought to determine whether a correlation exists between HRV and length of hospital stay, diagnosis of cerebral palsy, and neurodevelopmental test scores at 1-year corrected age. Time domain indices of HRV were computed longitudinally from 32 to 37 weeks of corrected gestational age in 19 very low birth weight, preterm infants. Among the 19 infants studied, 7 infants had no evidence of brain injury, 7 infants had periventricular leukomalacia (PVL), 3 infants had grade III/IV intraventricular hemorrhage (IVH), and 2 infants had both IVH and PVL. Neurologic injuries were documented using ultrasound and neurodevelopmental progress was followed through 1 year of corrected gestational age. A multivariate repeated measures analysis was performed to determine the relationship between the type of perinatal brain injury and neurodevelopmental status at 1 year of corrected gestational age. The type of perinatal brain injury was highly correlated to specific patterns of HRV with multivariate regression models producing adjusted r² values ranging from 0.63 to 0.99. The type of perinatal brain injury was highly correlated to the developmental outcome measures (p < 0.0000) with PVL patients having the lowest neurodevelopmental scores, IVH patients having the highest scores, and noninjured infants having midrange, grossly normal values. Using ANOVA, HRV was correlated to outcome, but individual comparisons revealed statistical significance only for the noninjured group (p < 0.04). However, multivariate models, which characterized outcome within each brain injury group, were highly significant (adjusted r ² ranged from 0.23 to 0.89). In summary, the type of perinatal brain injury determined the pattern of HRV and HRV was highly correlated to length of hospital stay and neurodevelopmental function assessed at 1 year of corrected gestational age.

Left ventricular mass and heart sympathetic activity after renal transplantation in children and young adults

“…Recently, analysis of HRV as a potent noninvasive clinical tool has been established in the pediatric population [25,26]. However, a few studies have evaluated sympathetic activity in patients after RT.…”

Autonomic dysfunction in uremia assessed by heart rate variability

“…The HRV method was successfully used in adults in a number of pathological conditions, including diabetes, cardiomyopathies, myocardial infarction, and brain injury [25,26,27,28]. The method was further established in pediatric diabetology, cardiology, traumatology, and neonatal medicine [29,30,31]. However, studies on uremic children are still lacking.…”

Prognostic Accuracy of Heart Rate Variability Analysis in Neonatal Encephalopathy: A Systematic Review

“…Loss of HRV occurs in traumatic brain injury and during seizures [9, 10], and is associated with brain injury and adverse neurodevelopment in very-low-birth-weight babies [11, 12]. In babies with birth asphyxia, the early identification of brain injury risk via HRV analysis could benefit patients by facilitating early disease stratification and the implementation of the most appropriate treatment.…”