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Biomedical subjects

J Hodgman

Publications and source records attributed to J Hodgman.

26 records · Page 2Linked to original sources
PubMed1978

Development of sinus arrhythmia during sleeping and waking states in normal infants.

The development of variability in heart rate (HR) due to respiration (sinus arrhythmia; SA) has been examined in normal infants from birth through the first 6 months of life. Two aspects of HR variation were examined: the absolute variation at the median respiratory frequency, or extent of sinus arrhythmia (XSA), and the degree to which HR follows respiration regardless of the absolute amount of variation, or coherence of sinus arrhythmia (CSA). Extent of sinus arrhythmia tended to be highest in quiet sleep (QS), lower in active or REM sleep (AS), and lowest in waking (AW), especially after 2 months of age. Extent declined at 1 month of age in QS, but rose over the first 6-month period in all states. During this same period, CSA was also highest in QS, lower in AS, and lowest in AW. Coherence in QS also declined at 1 month and rose between 1 and 6 months; however, no age effects were found in other states. Heart rate was negatively correlated with XSA, but less so with CSA. Sleep state appears to have a significant effect on cardiorespiratory coupling, and this coupling undergoes dramatic changes at 1 month in QS.

Arrhythmia, Sinus↗
PubMed1978

Polygraphic studies of normal infants and infants at risk for the sudden infant death syndrome: heart rate and variability as a function of state.

Spontaneous heart rate and variability were examined as a function of age and state from birth to 6 months of age in 10 normal infants and 10 infants at risk for sudden infant death syndrome (SIDS). The risk group showed a higher heart rate at 3 months of age, particularly in the waking state. The risk infants' heart rate also increased more markedly during the first month after birth in both quiet and active sleep. Heart rate in both groups declined after 2 months in every state; however, the risk infants lagged in the 2- to 3-month decline seen with the normal infants. In the awake state, heart rate variability in the risk group did not follow the increase seen with the normals during the 1-week to 2-month age period.

Age Factors↗
PubMed1977

Polygraphic studies of kitten development: sleep state patterns.

The sequence of developmental changes in sleep pattern organization was derived from 12-hr recordings in 10-, 20 and 40-day-old kittens. Each characteristic of sleep patterning exhibited a distinct maturational sequence. Earlier changes (10-20 days) included quiet sleep (QS) increments and somatic activity decrements; later changes (20-40 days) included emergence of EEG slow waves and spindles, decrements in active sleep (AS), and diminution of QS respiratory variability. Changes in the lengths of state epochs and the types of state transitions spanned the period studied. We suggest that the differential development of the characteristics of sleep patterns reflects differential maturation of distinct nervous system elements.

Age Factors↗
PubMed1976

Polygraphic studies of normal infants during the first six months of life. I. Heart rate and variability as a function of state.

This study examined spontaneous heart rate (HR) and variability as a function of age and sleep state in eight normal full term infants from birth to 6 months of age. Heart rates recorded during sleep were lower and less regular at 1 week (quiet sleep (QS) mean rate= 128, interquartile range = 6.4 beats/min; rapid eye movement (REM) = 134.5, 11.6) than at 1 month (QS = 138.6, 3.4; REM 139.6, 4.2). Rate decreased sharply from 1 to 3 months (QS = 118; REM 123.8) and decreased only slightly therafter (6-month QS = 113.5; REM 118.9). Variability decreased rapidly in REM from 2 to 4 months (from 11.4 to 9.1) and less quickly from 4 to 6 months (from 9.1 to 8.2), while QS variability decreased at 1 month (from 6.4 to 5.7) and became stable from that point (6.0 at 6 months). Waking heart rate and variability were both relatively low at 1 week (163, 11.2 beats/min) and increased from that age to 1 month (167.4, 14.3). Rate decreased rapidly in waking at 3 months (152 beats/min) and more slowly therafter (152 beats/min at 4 months, 149 beats/min at 6 months), whereas variability remained elevated until after 3 months, becoming stable at a lower level during later infancy (3 months = 14.8,6 months 11.7). Lowest values of rate and variability were found in QS and the highest values were found in waking at all ages, except at 1 week. Heart rates during REM closely approximated those in QS, whereas variability values more closely resembled those of waking.

Age Factors↗
PubMed1976

High risk perinatal care in California.

Rates of perinatal mortality are still too high in California. Mortality and morbidity, particularly for high risk pregnancies, can be reduced by the use of modern technology in the hands of highly trained personnel. New goals for perinatal care have been published by the California Medical Association reflecting these changes. This kind of care is too costly to be developed in all the small obstetric units presently providing services in California. Consolidation of obstetric and neonatal units into fewer hospitals can make it economically possible for these units to meet present-day standards.

California↗