[Unexpected natural death in street traffic].

All natural deaths of motor vehicle drivers and bicyclists in traffic were retrospectively studied from the police and forensic autopsy protocols in the province Uusimaa in 1982-1985. Of the cases 57 were males and 3 females. The annual prevalence of natural deaths at wheel greatly increased with the age and was 260 and 231 per 1 million drivers and bicyclists aged 60-69 years, respectively. The most common underlying cause of death was chronic ischaemic heart disease, often known before (42%), and often combined with acute myocardial infarction (62%). In about half of the cases there were injuries. However, only in 5 cases the injuries had contributed so death. The presence of alcohol and drugs did not play any role. These deaths differed significantly by the event and demography of the parties from those killed in traffic accidents. The results suggest that sudden deaths at wheel are not very common in Finland. However, in all kinds of traffic deaths the police investigation should be completed by the forensic autopsy.