Over the recent years, there have been some news reports on individuals who were normally healthy but died suddenly during or after exercising. Sudden cardiac death is one of the primary causes. According to clinical experience, two major factors were conducive to death: inherent illnesses and insufficient rescue.

The possibility of recessive disease should not be neglected even for those who are in good physical condition and engage in health examination regularly. Some symptoms such as paroxysmal arrhythmia may not be discovered through auscultation, electrocardiogram and cardiac ultrasound if such symptoms do not occur around the time of examination, needless to say that some examinations are just general health examinations. In addition, some may suffer from symptoms after health examinations. For example, acute myocarditis may not initially shows severe symptoms. Some patients may only feel tired as if they caught cold, but in the event of high heart load, the symptoms may deteriorate suddenly and arrhythmia may occur, which may even result in death. For patients at an old age, factors like coronary heart disease has to be considered as well, while young individuals also have to be cautious about the possibility of sudden cardiac death due to malignant arrhythmias. Generally speaking, it is often difficult to prevent sudden cardiac death because of its recessiveness. High-risk groups include those at the old age, those who have a family history of coronary heart disease, the obese, smokers, people who suffer from hypertension, diabetes and high blood lipids, and women who frequently take birth control pills, etc. The abovementioned groups should engage in risk assessment in health examination before exercising and comply with medical advice when exercising. We must be aware of our limit when exercising. Once symptoms such as pain in the anterior region of the back of the sternum, near-death feeling, cold sweats, and dizziness occur, we must stop exercising and seek help. We should not persist unreasonably.

Measures should be taken to recover the heart rate to prevent sudden cardiac death. When the heart has stopped beating for 4-6 minutes, brain cells will start to be damaged. Over 10 minutes without a functioning heart will result in brain tissue necrosis. Thus, scene rescue is very important. Measures for scene rescue primarily include CPR and AED. CPR stands for cardiopulmonary resuscitation, including practices such as chest compressions and artificial respiration. The advantage of this measure is that no extra tools are needed, as it can be conducted at any time, any place and any person. This measure can be taken once the heart of the patient stops. It is a global trend to promote CPR to all citizens. Effective CPR can raise every citizen's chance of being rescued.

AED refers to automatic external defibrillator, which is an important device used to rescue patients who are about to suffer from sudden cardiac death. Users can turn on the device and follow voice instructions. When electrode pads are attached to the patient, voice instructions will inform the users of the defibrillation timing and timing for CPR. Effective CPR can raise the chance of recovering a normal heart rate, increase the chance of survival and reduce the degree of cerebral ischemic injury. It is not difficult to operate AED as it is hard to find the device at any time. In general, AED devices are placed at public places such as airports. In developed regions, such devices have also been installed in big supermarkets for public use. In mainland China, communication apps such as WeChat can show the locations of AED. In Macao, AED can be found in the airport, ports, casinos and hospitals. The Macao government and some private institutions have conducted courses to enable residents to learn CPR and AED.