Sudden and unexpected death between 1 and 5 years.

Of a population of 9856 children followed up from birth, 9251 of whom underwent 24 hour tape recordings of electrocardiograms and abdominal wall breathing movements during early infancy, five died suddenly and unexpectedly at home at ages ranging from 16 months to 4 years. Postmortem examination, including full histological and microbiological investigations. failed to identify abnormalities ordinarily associated with death in all five cases. Two of the children were known to have had frequent cyanotic episodes and died during these events. In the three remaining cases there was no previous history of cyanotic or apnoeic episodes. The death of one of these three children was seen by his parents and the clinical features suggested that apnoea rather than a cardiac arrhythmia was the primary mechanism for his death. As in infancy, sudden and unexpected death for which no adequate cause is found at necropsy seems to constitute a major component of mortality between 1 and 5 years.