Sudden death is scary, but some of it can actually be avoided!

Author: Zhang Ping, Chief Physician of Beijing Tsinghua Chang Gung Hospital affiliated to Tsinghua University

Reviewer: Mi Yuhong, Chief Physician, Beijing Anzhen Hospital, Capital Medical University

Sudden death is a topic that scares everyone. Death occurs within an hour after the onset of clinical symptoms.

The main cause of sudden death comes from the heart. If it is not treated in time, the mortality rate is extremely high. Even if it is treated, the success rate is relatively low.

Figure 1 Original copyright image, no permission to reprint

1. What causes sudden cardiac death?

The most direct cause of sudden cardiac death is cardiac arrest due to poor heart rhythm.

Various diseases throughout the body can lead to sudden cardiac death, but the most common one is a problem with the heart itself, with the highest proportion being ischemic heart disease, also known as coronary heart disease.

In addition, heart failure, heart insufficiency, heart failure, primary cardiomyopathy, and primary arrhythmia can also easily lead to sudden death; and a small number of cases are due to sudden death caused by heart damage leading to heart rupture.

Other causes, such as electrolyte imbalance, excessive exercise, stress, and even fright, can also trigger malignant ventricular arrhythmias, leading to cardiac arrest and sudden death.

The incidence of sudden death varies with different disease states. Among people with myocardial infarction, sudden death accounts for about 10%. Among cardiomyopathies, the proportion of sudden death in patients with hypertrophic cardiomyopathy is higher, accounting for about 20% or 30% of the population; among people with heart failure in heart function level II and III, sudden death accounts for about 40%-60%.

2. Why does sudden cardiac death occur more often in patients with coronary heart disease?

In the 1990s, a set of anatomical data was collected abroad. Autopsies were performed on patients who died suddenly, and it was found that up to 90% of the deceased suffered from coronary atherosclerotic heart disease. It is not certain whether all of them died suddenly due to acute attacks of coronary heart disease, but it can be shown that coronary heart disease is the main cause of sudden cardiac death.

Coronary heart disease is caused by atherosclerosis of the coronary arteries. The detachment of plaques can block the blood vessels at any time. The moment the blood vessels are blocked, the myocardium is deprived of blood supply and necrosis will occur.

When the heart blood vessels are blocked, not only the myocardium will be damaged, but the heart's electrical conduction system will also be affected, causing it to become disordered, leading to arrhythmias such as rapid ventricular fibrillation, which can cause cardiac arrest and sudden death.

Figure 2 Original copyright image, no permission to reprint

Of course, there are also a small number of patients with coronary heart disease who suffer from heart rupture during acute myocardial infarction, which can also lead to sudden death.

3. Is there any pattern in the occurrence of sudden cardiac death?

There are some regularities in sudden cardiac death in life.

The incidence rate is higher in winter or at the junction of winter and spring because the cold can easily lead to acute coronary ischemia.

In a week, the incidence is higher on Mondays, and often in the early morning. This is because after the weekend break, people are very anxious to go to work on Monday. During this time in the early morning, the body is in a high sympathetic state, which causes high blood pressure, increases the incidence of myocardial ischemia and malignant arrhythmias.

In addition, people who smoke, are overweight, have bad tempers, and have sleep apnea syndrome have a higher risk of sudden death than ordinary people; the sudden death rate among the elderly is higher than that among young people.

4. Are there any signs before sudden cardiac death?

Sudden death means a very short period of time, and there will usually be precursors, but it is often too late to call for help or go to the hospital. For example, sudden death caused by myocardial ischemia often causes chest tightness and pain before it occurs.

During a football game, the famous football star Vivian Foe felt very uncomfortable, pressed his chest, and finally fell to the ground and died suddenly. This shows that he must have felt uncomfortable before his sudden death, which is why he pressed his chest. There were a first aid team and an emergency doctor on the scene, but his life could not be saved.

For people with this kind of aura symptoms, which are very short and cause sudden death immediately after the symptoms appear, we can only do some safety checks before exercise to reduce the occurrence of such a situation, but it is hard to prevent it. What can we do? Then we need to improve the national rescue capacity. Once sudden death occurs, emergency measures should be taken immediately, and cardiopulmonary resuscitation should be performed through the chest.

Some of the premonitory symptoms last longer and should be taken seriously, especially for people with risk factors, such as high blood pressure, high blood lipids, obesity, smoking, severe snoring, intermittent chest tightness and chest pain, which may be a long way from sudden death. If you have time, you can go to the hospital for a coronary angiography to check the stenosis of the coronary arteries, and revascularization in time, whether it is stent placement or bypass surgery, which can avoid sudden death and save lives. But many people do not pay attention to it and end up dying.