Sudden arrhythmic death syndrome: a national survey of sudden unexplained cardiac death.

To describe the characteristics of sudden arrhythmic death syndrome (SADS) and compare its incidence with official national mortality statistics for unascertained deaths. Sudden unexplained deaths were prospectively surveyed through 117 coroners' jurisdictions in England. Consecutive cases meeting the following criteria were included: white Caucasian, aged 4-64 years, no history of cardiac disease, last seen alive within 12 h of death, normal coroner's autopsy, cardiac pathologist's confirmation of a normal heart and negative toxicology. The estimated mortality from SADS was calculated and the official mortality statistics for unascertained causes of deaths in 4-64-year-olds was identified for the same time period. 115 coroner's cases were reported and 56 (49%) SADS victims were identified: mean age 32 years, range 7-64 years and 35 (63%) male. 7 of 39 cases (18%) had a family history of other premature sudden deaths (<45). The estimated mortality from SADS was 0.16/100 000 per annum (95% CI 0.12 to 0.21), compared with an official mortality of 0.10/100 000 per annum for International Classification of Diseases 798.1 (sudden death, cause unknown-instantaneous death) or 1.34/100 000 per annum for unascertained causes of death. Deaths from SADS occur predominantly in young males. When compared with official mortality, the incidence of SADS may be up to eight times higher than estimated: more than 500 potential SADS cases per annum in England. Families with SADS carry genetic cardiac disease, placing them at risk of further sudden deaths. SADS should therefore be a certifiable cause of death prompting specialised cardiological evaluation of families.