What is sudden cardiac death?

Unexpected natural death from a cardiac cause within short period of time. Death occurs <1 hour from onset of symptoms Death often contributed to arrhythmia, 40% unwitnessed (ECG only can provide definitive info) Prodromal nonspecific symptoms (ischemia (chest pain), tachyarrhythmia (palpitation) and congestive heart failure (dyspnea)