1.What is sudden death? The World Health Organization (WHO) considers sudden death to be the sudden death of a patient who is normally in good health or appears to be in good health, and who dies suddenly from a natural disease within an unexpectedly short period of time.” There is no unified standard regarding the time between onset and death; the WHO considers the time to be within 6 hours. However, it is mostly recognized that death within 1 hour of onset is mostly sudden death. 2.What is sudden cardiac death? Sudden cardiac death is a natural death caused by loss of consciousness within 1 hour after the onset of symptoms due to various cardiac causes. The main manifestations of sudden cardiac death are: death within 1 hour after an acute attack of chest pain and shortness of breath caused by cardiac causes; there are often no obvious signs before discovery; once it occurs, the effective rescue time is short. 3.What are the common causes of sudden cardiac death in young people? (1) Fatal arrhythmia: congenital hereditary tachycardia (Brugada syndrome, idiopathic ventricular tachycardia, long QT interval syndrome, etc.), which manifests as sudden ventricular tachycardia, or even ventricular flutter or ventricular fibrillation, leading to sudden cardiac arrest; in addition, bradycardia (such as third-degree atrioventricular block) can also lead to sudden cardiac death. Although most of these diseases have insidious onset and no pre-warning symptoms, most of them can be identified by electrocardiogram when they are not developed, and appropriate preventive measures can be taken. (2) Acute coronary syndrome: the most common of these is acute myocardial infarction. Coronary heart disease has a strong correlation with age, and young people are generally less likely to develop the disease. However, nowadays the trend of coronary heart disease is obviously younger, and the lipid level is several times higher than normal, which can easily cause lipid accumulation and cause coronary artery stenosis, and there will be frequent episodes of chest tightness, chest pain and other symptoms. (3) Hypertrophic obstructive cardiomyopathy: The patient’s hypertrophic myocardium will block the channels through which the heart pumps blood, causing acute ischemia in the brain and triggering sudden death. These patients have specific changes on examination of cardiac ultrasound and electrocardiogram, which can also be recognized early. (4) Severe fulminant myocarditis: Myocarditis usually occurs after a viral cold and is caused by a virus entering the bloodstream and infecting the heart muscle. There are obvious symptoms after the onset of the disease, such as severe chest tightness, weakness and dyspnea, and this condition is usually easy to recognize. (5) High-risk factors: In recent years, more and more young people are facing problems such as stressful study and work, unhealthy diet, irregular lifestyle, smoking and alcohol abuse, which increase the risk of sudden death and have become the main “killer” threatening the life and health of young people. When the heart function should be rested, some young people are still overworked, working late, lack of awareness of vigilance, and some young people drink a lot of alcohol, smoke, drink strong tea and coffee to improve sobriety and mental concentration, which in the long run will lead to a significantly higher risk of heart disease. 4.How can early detection and prevention be achieved? More than 1/4 of the population has experienced syncope or precordial syncope prior to the onset of cardiac arrest. If someone can make an emergency call when a patient has these prodromal symptoms, the survival rate of the patient can be greatly improved. (1) Pay attention to your own health status: Have a routine physical examination every year and pay attention to whether your ECG is abnormal and whether your blood pressure, blood lipids, and blood sugar are elevated. (2) Maintain a healthy lifestyle: avoid overeating, quit smoking, limit alcohol, and eat a healthy and reasonable diet. Avoid excessive mental tension or over-excitement, and maintain a good state of mind. (3) Pay attention to any uncomfortable symptoms: In the general population, white-collar workers and students with heavy school workload, if they feel tired, dizzy and headache, chest tightness, chest pain, panic and palpitations or fainting for a long time, they should be alert, adjust the pace of work and study, and it is recommended to consult a doctor early, or at least do an electrocardiogram and cardiac ultrasound to see if there are any common diseases of the heart. (4) Disease treatment and review: If you have congenital heart disease or hereditary heart disease you must be treated with regular check-ups and regular reviews.