Assessment of tobacco smoke effects on neonatal cardiorespiratory control using a semi-automated processing approach

Abstract

A semi-automated processing approach was developed to assess the effects of early postnatal environmental tobacco smoke (ETS) on the cardiorespiratory control of newborn lambs. The system consists of several steps beginning with artifact rejection, followed by the selection of stationary segments, and ending with feature extraction. This approach was used in six lambs exposed to 20 cigarettes/day for the first 15 days of life, while another six control lambs were exposed to room air. On postnatal day 16, electrocardiograph and respiratory signals were obtained from a 6-h polysomnographic recording. The effects of postnatal ETS exposure on heart rate variability, respiratory rate variability, and cardiorespiratory interrelations were explored. The unique results suggest that early postnatal ETS exposure increases respiratory rate variability and decreases the coupling between cardiac and respiratory systems. Potentially harmful consequences in early life include unstable breathing and decreased adaptability of cardiorespiratory function, particularly during early life challenges, such as prematurity or viral infection. Graphical abstract ᅟ.

Cardiorespiratory Alterations in a Newborn Ovine Model of Systemic Inflammation Induced by Lipopolysaccharide Injection

“…Our semiautomated processing approach, previously developed using Matlab R2013a software (The MathWorks Inc., Natick, MA, United States), was applied on the ECG and respiratory signals (Al-Omar et al, 2018). Each 6-h recording was automatically processed to extract all the 2-min stationary periods, which were considered to reflect the changes in autonomic state, according to previously proposed criteria (Borgnat et al, 2010).…”

“…It results from the central respiratory drive issued from the brainstem respiratory centers, whose activity is modulated by multiple internal factors of nervous and chemical origin; some random variability reflects system sensitivity to external stimuli. Linear analyses of RRV in the time domain were performed, as previously described, on Ttot (total breathing cycle duration) series (Al-Omar et al, 2018) and included mean and SD computation. Non-linear analyses of Ttot variability included Poincaré plots (SD1 and SD2) and SampEn.…”

“…Cardiorespiratory interrelations. The Pearson r 2 and the nonlinear h 2 correlation coefficients, the mean phase coherence γ RR,RESP , and the amplitude of the respiratory sinus arrhythmia (RSA, the difference between the maximum and the minimum RR in a respiratory cycle) (Carroll et al, 2012) were calculated, as previously detailed (Al-Omar et al, 2018).…”

Influence of Moderate Hyperbilirubinemia on Cardiorespiratory Control in Preterm Lambs

“…Our previously developed semi-automated processing approach was applied on ECG and RESP signals recorded from non-sedated animals. Each step of the developed approach, represented in Figure 2, has been detailed previously (Al-Omar et al, 2018) and is briefly presented hereafter.…”

“…As previously detailed (Al-Omar et al, 2018), linear HRV analysis included measurements in both the time-domain [mean; standard deviation, SD; coefficient of variation (%) = ratio of SD to the mean (Harrington et al, 2003); mean squared differences of successive RR intervals, RMSSD; skewness and kurtosis] and the frequency domain [power in the low-frequency (LF, 0.02–0.25 Hz) and high-frequency (HF, 0.25–2 Hz) spectral bands, total power, LF/HF ratio]. Nonlinear analyses included SD1 and SD2 from the Poincaré plot, sample entropy (SampEn), detrended fluctuation analysis (alpha1) and deceleration (DC) and acceleration (AC) capacities (Campana et al, 2010; Pan et al, 2016).…”