 Acute non-traumatic chest pain is a common kind of symptom in extremely critical condition, with various pathogenesis and different level of risk . Chest pain in high risk takes 13 of that. It mainly includes acute coronary syndrome including myocardial infarction and unstable angina pectoris, accounted for over 95 of chest pain in high risk, aortic dissection, pulmonary embolism etc, and is in high lethality and deformity. 