QTc and R-R intervals in victims of the sudden infant death syndrome
S. L. Weinstein and A. Steinschneider
Electrocardiograms obtained during sleep within the first and/or fourth
week postnatally were available on eight infants who subsequently died of
the sudden infant death syndrome (SIDS). The corrected QT (QTc) and R-R
intervals were compared with controls for the purpose of evaluating their
relevance for SIDS. The QTc interval in controls increased with age and
tended to be longer during sleep without rapid eye movements. The R-R
interval decreased with age. None of the SIDS victims was found to have a
prolonged QTc interval. However, the R-R interval during rapid eye movement
epochs was significantly shorter in future SIDS victims compared with
controls. These data were interpreted as being inconsistent with the
congenital variants of the long-QT hypothesis but compatible with the
growing conviction that infants who die of SIDS have a chronic underlying
abnormality that has subtle manifestations within the immediate postnatal
period.
