Sudden death events are often preceded by “early warning” symptoms, but recognition is difficult, especially in non-surviving patients. Patients who die suddenly and are resuscitated often have retrograde amnesia and therefore do not remember events or symptoms that may have occurred. Some studies have shown that chest pain and dyspnea are the most common symptoms, and patients with heart disease-related symptoms, especially new or unstable symptoms, should seek immediate medical attention for potentially life-saving evaluation and treatment. It is recommended that people are able to take care of themselves in order to reduce the incidence of sudden death.