Heart rate variation in normal infants and victims of the sudden infant death syndrome

Dynamic Analysis of Cardiac R-R Intervals in Normal Infants and in Infants Who Subsequently Succumbed to the Sudden Infant Death Syndrome

“…This pattern is not unexpected, inasmuch as both heart rate and overall heart rate variation show similar developmental patterns [heart rate increases rapidly over the first week of life, then decreases, and overall heart rate variation decreases in the early postnatal period and increases thereafter (2,4)J. It is interesting, however, that the SIDS victims do not show this developmental pattern of sustained changes, although they do show the characteristic patterns of maturation of heart rate and overall heart rate variation (2,4). Furthermore, although some SIDS victims showed almost as many sustained changes as the controls, another subset of the SIDS victims showed a profound reduction in these values (Fig.…”

“…During QS, for example, short-term heart rate variation is enhanced and overall variance reduced relative to those values found in REM sleep (1 3). Furthermore, certain differences previously identified between SIDS victims and controls are apparent only during particular sleep-waking states (2,4). We examined instantaneous and long-term changes in cardiac beat-to-beat intervals during sleep and AW states in control infants and infants who later succumbed to SIDS.…”

“…We speculate that the autonomic disturbance may lead to cardiac instability or may indicate CNS alterations with the potential to affect other vital functions. (Pediatr Res 31: 606-612,1992) Abbreviations AW, waking QS, quiet sleep REM, rapid eye movement SIDS, sudden infant death syndrome ANOVA, analysis of variance Infants who subsequently succumb to SIDS demonstrate higher heart rates, diminished heart rate variation associated with respiration, and disturbed long-term coordination of cardiac and respiratory measures relative to age-matched controls (1)(2)(3)(4)(5). Some of these differences are apparent only in particular sleepwaking states (2,4,6).…”

“…(Pediatr Res 31: 606-612,1992) Abbreviations AW, waking QS, quiet sleep REM, rapid eye movement SIDS, sudden infant death syndrome ANOVA, analysis of variance Infants who subsequently succumb to SIDS demonstrate higher heart rates, diminished heart rate variation associated with respiration, and disturbed long-term coordination of cardiac and respiratory measures relative to age-matched controls (1)(2)(3)(4)(5). Some of these differences are apparent only in particular sleepwaking states (2,4,6). We examined respiratory patterning to determine the factors underlying the differences in heart rate variation and found fewer respiratory pauses in the SIDS victims (7); however, respiratory rate and its overall variability did not differ significantly from those of control infants (2).…”

Cerebral Oxygenation in Preterm Infants

“…4 SIDS peaks in incidence at 2 to 4 months of age 5,6 and is believed to involve an uncompensated cardiovascular event presumed to occur during sleep, in conjunction with failure of the life-saving arousal response. [7][8][9][10][11] Preterm infants exhibit immature cardio-respiratory control, which persists past term-equivalent age, 12 is related to gestational age (GA) at birth, 13,14 and may contribute to their heightened risk for SIDS. 15 Prone sleeping is a major risk factor for SIDS, particularly among infants born preterm.…”