Evaluation of the autonomic nervous system by analysis of heart rate variability in the preterm infants

Abstract

Background Premature infants may present with damage to the autonomic nervous system (ANS), which may be related to poorer neurological development. Among the techniques used to evaluate the ANS, heart rate variability (HRV) emerged as a simple, non-invasive, and easy to apply tool. The aim of the present study was to analyze and compare HRV in preterm infants at different times of hospitalization in order to verify the possible environmental relationships or clinical evolution with HRV. Methods A longitudinal, prospective, and descriptive study with non-probabilistic sampling composed of 25 collections of preterm infants of HRV at two moments: moment I (within 15 days of birth) and moment II (after 45 days post-birth). The Polar V800 heart rate monitor was used with the Polar H10 cardiac transducer to collect HRV, which was collected in the supine position for 15 min. The HRV data were analyzed by the linear method in frequency domain and time domain and by the nonlinear method using Kubios HRV analysis software, version 3.0.2. Results There was an increase in HRV values at moment II, these being statistically significant in the SD1, ApEn, and SampEn. Data related to increased sympathetic nervous system activity, parasympathetic nervous system activity, and increased index complexity. Conclusions The data demonstrate an increase in HRV values in premature infants at moment II, demonstrating a possible development in the maturation of the ANS during hospitalization. Trial registration: RBR-3x7gz8 retrospectively registered. Electronic supplementary material The online version of this article (10.1186/s12872-019-1166-4) contains supplementary material, which is available to authorized users.

Maturation of the Autonomic Nervous System in Premature Infants: Estimating Development Based on Heart-Rate Variability Analysis

“…These results are not simply in line with a decrease of by Hoyer et al ( 2013 ), but they are also supported by other clinical findings. Namely, an increase of the short-term variability of the tachogram was found during the first days of life (De Souza Filho et al, 2019 ) and the absolute LF power can discriminate preterm and full-term infants with 84% accuracy (Mulkey et al, 2018 ). However, the highest performances in the PB and BB schemes are achieved when the fractal and spectral features are combined, as highlighted in bold in Table 4 and suggested by the concomitant increase of entropy and short-term variability of HRV found by De Souza Filho et al ( 2019 ).…”

“…Namely, an increase of the short-term variability of the tachogram was found during the first days of life (De Souza Filho et al, 2019 ) and the absolute LF power can discriminate preterm and full-term infants with 84% accuracy (Mulkey et al, 2018 ). However, the highest performances in the PB and BB schemes are achieved when the fractal and spectral features are combined, as highlighted in bold in Table 4 and suggested by the concomitant increase of entropy and short-term variability of HRV found by De Souza Filho et al ( 2019 ). Interestingly, the highest performances are also achieved when the between bradycardias epochs are considered ( MAE = 1.56 weeks), which further reveals a bias effect of bradycardias in the description of autonomic maturation.…”

Heart Rate Variability in the Perinatal Period: A Critical and Conceptual Review

“…Several studies showed the usefulness of non-linear metrics over linear ones in evaluating the autonomic development (Uhrikova et al, 2015;de Souza Filho et al, 2019;Oliveira et al, 2019b), the interactions between ANS, brain, and stress axis (Thayer and Lane, 2000), and the infant's adaptation capacity (Gonçalves et al, 2017;Shaffer and Ginsberg, 2017;Urfer-Maurer et al, 2018).…”

Technical Innovation for Visual Assessment of Preterm Newborns in a Neonatal Intensive Care Unit: Exploratory Study

“…Autonomic modulation, estimated by heart rate variability (HRV) and regulated by sympathetic and parasympathetic pathways, has been increasingly used as a measure of term and preterm newborn stress and well-being [ 1 – 3 ].…”