Sudden death, although sudden, is actually traceable, especially for people at risk of cardiovascular disease, we should pay special attention to the following abnormal performance. 1, the recent appearance or aggravation of chest tightness, if the recent sudden appearance of chest tightness after activity, rest for a period of time can be relieved, this phenomenon suggests that may be suffering from coronary heart disease, sudden symptoms indicate that the plaque in the coronary arteries is unstable and may rupture at any time. 2, panic, panic is often the feeling of accelerated heart rate, irregularly appearing heart rate accelerated, usually the result of rapid arrhythmia, most of the arrhythmia is less dangerous, will not occur sudden cardiac death, if frequent episodes of ventricular arrhythmia, may develop into the risk of ventricular fibrillation symptoms. 3, bradycardia, the beating of the heart is initiated by a specific pacemaker cells If the pacing cells become poorly functioning, the heart rate will slow down, which can lead to cardiac arrest in severe cases. 4. syncope, syncope is an important precursor of sudden death, and most syncope is caused by a sudden slowing or stopping of the heart, resulting in insufficient blood supply to the brain. 5. blackness before the eyes and numbness of the limbs, stroke is also an important cause of sudden death. 6. pain, pain response is the most easily caught and perceived sign of the onset of sudden death. The signal that is caught and perceived. Be highly alert when you feel a sudden, sharp, crushing pain in the chest and feel breathless.