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Your search keyword '"Schechtman, Vicki L."' showing total 19 results
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19 results on '"Schechtman, Vicki L."'

2. Sleep state organization in normal infants and victims of the sudden infant death syndrome

Author

Schechtman, Vicki L., Harper, Ronald M., Wilson, Arian J., and Southall, David P.

Subjects
Sudden infant death syndrome -- Risk factors, Sleep-wake cycle -- Health aspects, Sleep -- Physiological aspects
Abstract

Infants at increased risk of the sudden infant death syndrome (SIDS) show abnormal patterning of sleep-waking states. It was hypothesized that infants who were to die of SIDS would show abnormalities of sleep state distribution prior to their deaths. Twenty-two 12-hour recordings were obtained from infants who subsequently died of SIDS, and sleep state patterns were compared in these records and 66 records of age-matched control infants. Each 1-minute epoch was classified as quiet sleep, rapid eye movement (REM) sleep, waking, indeterminate state, or artifact-contaminated. Victims of SIDS showed less waking and more sleep than control infants during the early-morning hours. Victims of SIDS younger than 1 month of age showed significantly more epochs classified as REM sleep across the night and significantly fewer epochs contaminated by artifacts relative to control infants. Further analysis indicated that the increased number of REM epochs resulted from fewer artifact-contaminated epochs, suggesting reduced motility during REM sleep in the SIDS victims compared with the control infants. The finding of decreased waking time during the early morning is of particular importance since most SIDS deaths occur during this portion of the day. The findings of altered sleep patterns in SIDS victims suggest that central neural changes are associated with SIDS risk. Pediatrics 1992;89:865-870

Published
1992

3. Sleep apnea in infants who succumb to the sudden infant death syndrome

Author

Schechtman, Vicki L., Harper, Ronald M., Wilson, Adrian J., and Southall, David P.

Subjects
Sudden infant death syndrome -- Development and progression, Apnea -- Physiological aspects, Sleep apnea syndromes -- Development and progression
Abstract

Infants at risk for sudden infant death syndrome (SIDS) have slight abnormalities in various physiological functions, including increased heart and breathing rates. Various characteristics of apnea (pauses in breathing) have been reported in SIDS infants, including differences in the number of apneic pauses. These pauses may differ during various stages of sleep. The frequency and duration of apneic pauses during the stages of quiet sleep and rapid eye movement were examined in 22 infants between 2 to 65 days of age, who subsequently died of SIDS, and 66 control infants. During the first month of life, no difference was seen in the number of breathing pauses in the infants who died of SIDS and the control infants. However, during the second month of life, from 40 to 65 days, the SIDS infants showed fewer breathing pauses than control infants in both sleep states. Therefore, the time period of breathing irregularities was occurred in the second month of life. This precedes the time when infants are at the greatest risk for SIDS, which is from two to six months of age. This finding may provide some insight into the cause of SIDS. (Consumer Summary produced by Reliance Medical Information, Inc.)

Published
1991

4. Nonlinear dynamics of heart rate variability in cocaine-exposed neonates during sleep

Author

GARDE, SMITA, REGALADO, MICHAEL G., SCHECHTMAN, VICKI L., and KHOO, MICHAEL C. K.

Subjects
Children of drug addicts -- Physiological aspects, Heart beat -- Measurement, Infants (Newborn) -- Physiological aspects, Biological sciences
Abstract

The aim of this study was to determine the effects of prenatal cocaine exposure (PCE) on the dynamics of heart rate variability in full-term neonates during sleep. R-R interval (RRI) time series from 9 infants with PCE and 12 controls during periods of stable quiet sleep and active sleep were analyzed using autoregressive modeling and nonlinear dynamics. There were no differences between the two groups in spectral power distribution, approximate entropy, correlation dimension, and nonlinear predictability. However, application of surrogate data analysis to these measures revealed a significant degree of nonlinear RRI dynamics in all subjects. A parametric model, consisting of a nonlinear delayed-feedback system with stochastic noise as the perturbing input, was employed to estimate the relative contributions of linear and nonlinear deterministic dynamics in the data. Both infant groups showed similar proportional contributions in linear, nonlinear, and stochastic dynamics. However, approximate entropy, correlation dimension, and nonlinear prediction error were all decreased in active versus quiet sleep; in addition, the parametric model revealed a doubling of the linear component and a halving of the nonlinear contribution to overall heart rate variability. Spectral analysis indicated a shift in relative power toward lower frequencies. We conclude that 1) RRI dynamics in infants with PCE and normal controls are similar; and 2) in both groups, sympathetic dominance during active sleep produces primarily periodic low-frequency oscillations in RRI, whereas in quiet sleep vagal modulation leads to RRI fluctuations that are broadband and dynamically more complex. autonomic function; cardiovascular control; infants; modeling

Published
2001

16. Spectral Analysis Assessment of Respiratory Sinus Arrhythmia in Normal Infants and Infants Who Subsequently Died of Sudden Infant Death Syndrome

Author

KLUGE, KAREN A., HARPER, RONALD M., SCHECHTMAN, VICKI L., WILSON, ADRIAN J., HOFFMAN, HOWARD J., and SOUTHALL, DAVID P.

Abstract

Reduced heart rate variability has been found in infants who later succumb to the sudden infant death syndrome (SIDS). To determine whether respiratory sinus arrhythmia, a major component of heart rate variability, is also reduced in SIDS victims, nighttime portions of eighteen 24-h recordings of ECG and respiration from infants who later died of SIDS and 52 recordings from control infants were assessed using spectral analysis. Two aspects of respiratory sinus arrhythmia were examined: “extent” (the absolute heart rate variation at the respiratory frequency) and “coherence” (the degree to which heart rate follows respiration regardless of the absolute amount of variation). Respiratory parameters were used to classify each 1-min epoch as quiet sleep, rapid eye movement sleep, waking, or indeterminate state. Median extent and coherence values across the night were then computed for each sleep-waking state. Two-way (group ± state) repeated measures analysis of variance tests were then used to compare respiratory sinus arrhythmia values for 13 SIDS victims and 13 control infants matched by postnatal age, birth weight, sex, and gestational age. Extent of respiratory sinus arrhythmia was significantly lower in the SIDS victims across all sleep-waking states, a finding that persisted after adjusting for heart rate. Coherence values did not differ significantly. These results suggest that even before the time of maximal risk for the syndrome, SIDS victims, as a group, differ from controls in the extent to which cardiac and respiratory activity couple, and this difference is independent of basal heart rate.

Published
1988

17. Development of Heart Rate Variation Over the First 6 Months of Life in Normal Infants

Author

SCHECHTMAN, VICKI L., HARPER, RONALD M., and KLUGE, KAREN A.

Abstract

Development of heart rate variation in three frequency ranges was examined during sleep-waking states in normal infants over the first 6 mo of life. Extent of all three types of heart rate variation decreased from 1 wk to 1 mo of age. Extent of respiratory sinus arrhythmia increased from 1 mo to 6 mo during all sleep-waking states, with the increase most pronounced during quiet sleep. Variation in two hands of lower frequencies showed increases in extent from 1 to 3 mo, then a slowing or reversal of the increase between 3 and 4 mo of age. During rapid eye movement sleep, the two types of lower frequency heart rate variation decreased in extent from 3 through 6 mo of age. These results suggest that alterations in autonomic control of heart rate occur at several time periods over the first 6 mo of life and that these alterations may have an effect only on particular types of heart rate variation and only during particular sleep-waking states. The diminution of all three types of heart rate variation at 1 mo may indicate a reduction in vagal tone at this age.

Published
1989

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