The electrophysiologic features of sudden death.

Sudden or instantaneous death is nearly always of cardiac origin. The most common mechanism is a severe electrical dysfunction, which is apparent on Holter monitoring tapes. Identifying patients at risk of sudden cardiac death is difficult, and Holter monitoring has proved to be limited in its diagnostic usefulness. However, in patients who have experienced cardiac arrest Holter monitoring has shown that the electrical abnormalities leading to death vary. These abnormalities usually take time to develop, and during this time the cerebral circulation is partially maintained. In this brief period, lasting less than 2 minutes, the individual may become aware that something is wrong and have time to react.