Sudden unexpected cardiac death: methods and results of a national pilot survey

In order to develop a methodology for measuring the occurrence and circumstances of sudden unexpected adult deaths due to cardiac and to unidentified causes throughout England, a stratified random pilot sample of 12 of the 133 coroner's jurisdictions in England was invited to survey prospectively a quota sample of 78 consecutive white Caucasians, aged from 16 to 64 years, with no history of ischaemic heart disease, who were last seen alive within 12 h of being found dead, and for whom a coroner's post-mortem examination found either a cardiac or no identifiable cause of death. Eleven (92%) coroners participated. In a median of 105 days (range 21-169), 65 cases (83% of the quota) were ascertained (54 (83%) males). Of the ascertained cases, registration forms were received on 62 (95%), tissue specimens on 63 (97%), and post-mortem reports on 58 (89%). Death was witnessed in 58%, of which 35% were 'instantaneous'. The median time from symptom onset to death was 40 min. In unwitnessed deaths, the median time since last being seen alive was 90 min. Sixty-eight per cent of all deaths were attended--by a relative in 34%, passer-by (8%), ambulance crew (32%), nurse (11%), doctor (38%), and police (9%). Cardio-pulmonary resuscitation was attempted in 38 of the 42 attended deaths. Sixty-seven per cent were taken ill at home, 12% at work, 12% in a public place, and 10% elsewhere. The certified cause of death was ischaemic heart disease in 89%, in whom coronary thrombosis and/or myocardial damage was absent in 6 cases (9%). In the remainder, the certified cause was hypertensive heart disease (5%), hypertrophic obstructive cardiomyopathy (3%), 'cardiomegaly' (1.5%) and 'sudden cardiac arrhythmia' alone (1.5%). A retrospective audit of coroner's records revealed the median case ascertainment rate was 75%. This approach to surveying sudden unexpected adult death nationally resulted in a high response rate (92%) from coroners, consultant pathologists and their staff, the identification of a large proportion of eligible cases, and complete information in most of the identified cases. In from 2% to 15% of cases, death may have been either purely dysrhythmic or due to a sudden adult death syndrome.