Sudden death isn't always so sudden. Chest pain, shortness of breath, and other common heart attack warning signs often precede sudden cardiac arrest.
D016887:Cardiopulmonary Resuscitation / Q000706:statistics & numerical data; D002637:Chest Pain / Q000209:etiology; D016757:Death, Sudden, Cardiac; D004244:Dizziness / Q000209:etiology; D004417:Dyspnea / Q000209:etiology; D006801:Humans; D009325:Nausea / Q000209:etiology; D014839:Vomiting / Q000209:etiology