Sudden unexpected cardiac death among Tasmanian men.

OBJECTIVE

To examine sudden unexpected cardiac death (SUCD) in Tasmanian men and to assess the contribution of these deaths to differences in rates of mortality from ischaemic heart disease (IHD) between regions within Tasmania.

DESIGN AND SETTING

Descriptive epidemiological study based in the community.

SUBJECTS

Male residents of Tasmania aged 30 to 69 years who died from IHD suddenly and unexpectedly between 1987 and 1989.

MAIN OUTCOME MEASURES

Rates and proportions of sudden cardiac death in men who had no prior overt signs of IHD, validated by necropsy and information from the attending doctors.

RESULTS

SUCD accounted for approximately 24% of deaths from IHD among men aged 30 to 69 years in Tasmania. The ratios of observed to expected numbers of deaths occurring among manual and nonmanual workers were similar whereas there was an excess of events among men aged less than 65 years who were not working. Examination of data from necropsy reports revealed that 32% of cases showed evidence of previous "silent" myocardial infarction and 63% showed severe coronary artery disease in two or more vessels, with a further 28% having severe single vessel disease. The contribution of SUCD to total mortality from IHD varied from 20% in the north-west region to 25% in the south and 26% in the north, but the limited number of events makes it uncertain whether the variation in the rate of SUCD is significantly different from that for total mortality from IHD.

CONCLUSIONS

The proportion of deaths from IHD among men in Tasmania which are sudden and unexpected and the associated necropsy findings are consistent with those described in other population based studies of sudden cardiac death. Non-participation in the workforce was a risk factor in SUCD. As yet, we cannot distinguish whether the higher mortality rates from IHD among men in northern regions of Tasmania (P < 0.01) were due to differences in SUCD or whether the same rate of SUCD obtains in all regions of the State and the differences in mortality from IHD reflect variation in non-sudden deaths and deaths in people with overt IHD.