Fetal development of complex autonomic control evaluated from multiscale heart rate patterns

Abstract

U. Fetal development of complex autonomic control evaluated from multiscale heart rate patterns. Am J Physiol Regul Integr Comp Physiol 304: R383-R392, 2013. First published December 26, 2012 doi:10.1152/ajpregu.00120.2012.-Development of the fetal autonomic nervous system's integrative capacity in relation to gestational age and emerging behavioral pattern is reflected in fetal heart rate patterns. Conventional indices of vagal and sympathetic rhythms cannot sufficiently reflect their complex interrelationship. Universal behavioral indices of developing complex systems may provide additional information regarding the maturating complex autonomic control. We investigated fetal magnetocardiographic recordings undertaken at 10-min intervals in active (n ϭ 248) and quiet (n ϭ 111) states between 22 and 39 wk gestational age. Standard deviation of heartbeat intervals, skewness, contribution of particular rhythms to the total power, and multiscale entropy were analyzed. The multiscale entropy methodology was validated for 10-min data sets. Age dependence was analyzed by linear regression. In the quiet state, contribution of sympathovagal rhythms and their complexity over a range of corresponding short scales increased with rising age, and skewness shifted from negative to positive values. In the active state, age dependencies were weaker. Skewness as the strongest parameter shifted in the same direction. Fluctuation amplitude and the complexity of scales associated with sympathovagal rhythms increased. We conclude that in the quiet state, stable complex organized rhythms develop. In the active state, however, increasing behavioral variability due to multiple internal coordinations, such as movement-related heart rate accelerations, and external influences develop. Hence, the state-selective assessment in association with developmental indices used herein may substantially improve evaluation of maturation age and early detection and interpretation of developmental problems in prenatal diagnosis. autonomic nervous system; complexity; developmental biology; fetal maturation; fetal behavioral patterns THERE IS INCREASING CONSENSUS that a certain number of diseases such as cardiovascular disease, metabolic syndrome, atherosclerosis, Type 2 diabetes, learning difficulties, hyperkinetic disorders, as well as cognitive, behavioral, and emotional problems in late postnatal age are associated with adverse influences during fetal development that became permanently programmed (1,2,4,10,11,19,20,23,24,26,31,32,39,40,44,47). However, early identification of fetal developmental problems is a challenging topic of prenatal diagnosis due to the extremely limited number of observable variables from the fetus. During the fetal maturation the emerging complex behavioral patterns are associated with an increasing functional integration in the organism. In that connection the autonomic nervous system (ANS) plays a predominant role for complex coordinated control of multiple vitally important physiological subsystems in the organism. Sin...

Formation of functional associations across time scales in the fetal autonomic control system — A multifractal analysis

“…The high predictive value of SDNN and VLF in several clinical studies is discussed as being caused by the integrative consideration of faster vagal and sympathetic control in the overall cardiovascular system (Taylor et al 1998, Stein 2005. Furthermore, the inverse association between shorter scales and longer scale complexity found in connection with pathological disturbances (Hoyer et al 2007) as well as during the fetal maturation (Hoyer et al 2013a) can be interpreted as related to integrative controlling networks that are interconnected over several time scales.…”

“…Power spectral analysis showed the development of heart rate variability such as the vagal and sympathetic rhythms and the slower integrative ones (van Leeuwen et al 2003, David et al 2007. Single scale complexity indices were interpreted as representing the overall complex interaction (van Leeuwen et al 1999 and2006), multiscale complexity indices and functions provided additional information about several control time horizons (Frank et al 2006, Ferrario et al 2009and 2013a. Universal aspects of developmental biology and self-organization constituted fetal autonomic brain age score (Hoyer et al2013b) and, finally, correlations over the time scale turned out to be important information about the growing, and increasingly interacting integrative control system , Gierałtowski et al 2013).…”

“…The methodology is identical to that of previous studies and given in more detail there (e.g. Hoyer et al 2013a). …”

“…The development of more elaborate concepts may improve the fitting to the observed behavior of the complicated physiological system of cardiovascular control. Fetal heart rate variability amplitude and complexity analysis across time scales showed the formation and development of this complex control system in the course of gestational age , 2013a, Gierałtowski et al 2013. But the diversity of methods used and of the results obtained is high and key parameters such as those that are related to the maturating dependencies across time scales are lacking.…”

“…2013b). Dependencies in complexity across time scales were described by multiscale entropy functions over coarse graining scales of 1-20 (Hoyer et al 2013a). Furthermore, multiscale multifractal analysis (MMA) was adapted to short (30 min) recordings of fetal heart rate and applied to a data set of quiet sleep behavior (Gierałtowski et al 2013).…”