Snapshot A 52-year-old man was eating dinner with his family before unexpectedly collapsing. He was recently diagnosed with an ST-segment elevation myocardial infarction affecting his anterolateral heart. In the emergency room, an electrocardiogram demonstrates ventricular tachycardia. Despite resuscitative efforts, he dies within the next 30 minutes. Introduction Clinical definition unexpected death secondary to cardiac causes within 1 hour of symptom onset Epidemiology risk factors coronary artery disease (leading cause) hereditary or acquired cardiac conduction abnormalities congenital coronary artery abnormalities myocardial hypertrophy mitral valve prolapse Pathogenesis most often due to a lethal arrhythmia such as asystole ventricular fibrillation ventricular tachycardia Prognosis early effective medical intervention and implantable automatic cardioverter defibrillators improve outcomes