Study of the conduction system in a population of patients with sudden infant death syndrome.

The conduction system of 23 infant hearts, 15 of sudden infant death syndrome (SIDS) and eight of those dying from known cause, was serially sectioned. A left-sided His bundle was found more commonly in (SIDS) (eight of 15) than in the controls (two of eight). Taking into account a previous study in which a left-sided His bundle was found in only four of 32 hearts from all age groups, this is statistically significant and may be a factor promoting SIDS.