Table 1

Definitions of sudden death (SD) and sudden cardiac death (SCD)

TermDefinition
SD A sudden, natural and unexpected death.
Definite SD An SD with established time frame from change in cardiovascular status to death:
  • In witnessed cases: an acute change in cardiovascular status with time to death <1 hour;

  • In unwitnessed cases: the deceased seen alive and functioning normally <24 hours before being found dead.

Probable SD Death in a person without fully established time frame from change in cardiovascular status to death with cause of death likely to be SD in an otherwise healthy person free of any chronic and/or severe diseases expected to lead to a non-SD.
SCD
Definite SCD Autopsied definite SD of unknown or cardiac cause.
OR
SD with documented ventricular arrhythmia immediately preceding death.
Probable SCD Non-autopsied definite SD presumed to be of cardiac origin after review of all available information.
Possible SCD Non-autopsied probable SD presumed to be of cardiac origin after review of all available information.