Sudden cardiac death syndrome

Introduction to sudden cardiac death syndrome Sudden death is a clinical syndrome, in which it seems that health or the condition has basically recovered or stabilized, and unexpected non-human death suddenly occurs. Most occur within an hour after an acute onset, up to a maximum of 6 hours, mainly due to primary ventricular fibrillation, ventricular arrest or electromechanical separation, resulting in a sudden stop of the effective contraction function of the heart. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: sudden death

Cause of sudden cardiac death syndrome

Coronary heart disease (20%):

It is the most common cause of sudden death in heart. Coronary heart disease is a common disease in middle-aged and elderly people. It is frequently afflicted and seriously endangers human life. Most people do not have any symptoms, work, study, and life as usual, but often have signs of myocardial ischemia, such as feeling uncomfortable, or fatigue symptoms, although the symptoms are very mild, but if you do an electrocardiogram in time, you will find the heart muscle Ischemic conditions can be prevented as soon as possible.

Rheumatic heart disease (20%):

About 25% of patients with aortic stenosis can cause sudden death, and rheumatic heart disease is referred to as rheumatic heart disease, which refers to heart valve disease caused by rheumatic fever activity involving heart valves. There are one or several stenosis and/or regurgitation in the mitral, tricuspid, and aortic valves.

Myocarditis (10%):

Severe myocarditis can have diffuse myocardial lesions, leading to cardiogenic shock and sudden death.

Primary cardiomyopathy (10%):

The lesion is mainly invading the ventricle and may also involve the heart conduction system.

QT interval prolongation syndrome: including congenital deafness, secondary causes are commonly caused by hypokalemia, quinidine, amiodarone drugs.

Mitral valve prolapse syndrome (10%):

Often cause a rapid arrhythmia.

Congenital heart disease - coronary artery malformation: such as the left coronary artery originating from the right coronary sinus or connected to the right coronary artery.

Pre-excitation syndrome with atrial fibrillation: The shorter the refractory period of the bypass, the more likely it is to become a malignant arrhythmia - ventricular fibrillation and sudden death.

Sick sinus syndrome: mostly due to coronary disease, myocarditis, cardiomyopathy, sinus node ischemia, degeneration, sinus node ischemia, necrosis, fibrosis.

Sudden death syndrome

Comprehensive prevention of sudden cardiac death in coronary heart disease

1. Application of -blockers: In a research center in Europe in 1970, it was pointed out that -blockers can reduce the mortality of muscle infarction. A large clinical trial of a control group to observe -acceptance after acute myocardial infarction The rate of survival of the blockers in one year is higher than that of the control group. Most scholars advocate long-term use of -blockers to reduce myocardial oxygen consumption and reduce myocardial infarct size while membrane stability reduces ventricular arrhythmia.

2. Coronary artery endovascular or coronary artery bypass surgery for patients with myocardial ischemia caused by severe coronary artery stenosis undergoing coronary angioplasty with balloon dilatation stenosis to significantly improve coronary blood supply to left main coronary artery stenosis Or more than three patients with severe coronary artery stenosis and patients with ventricular aneurysm after acute myocardial infarction undergo coronary artery bypass surgery and ventricular aneurysm resection to reduce the incidence of sudden cardiac death.

3. Implanted in vivo embedded automatic defibrillator: This is a new method to achieve initial results. When ventricular tachycardia or ventricular fibrillation occurs, the electrode of the automatic defibrillator can be emitted according to the perceived ECG. Joule's electrical energy for cardioversion can treat both ventricular fibrillation and prevent sudden death.

Complications of sudden cardiac death syndrome Complications

If the rescue is not timely, it will lead to death and no other complications.

Symptoms of Sudden Death Sudden Syndrome Common Symptoms Purpura, fatigue, sleep, sudden death, dyspnea, slow breathing, irregular palpitations, anterior palpebral palpebral death, photoreaction, disappearance, convulsion

There may be no signs before sudden death. Some patients have mental stimulation and mood swings before sudden death, some have pain in the precordial area, and may be accompanied by difficulty breathing, palpitations, extreme fatigue, or acute myocardial infarction. Ventricular premature beats, when sudden death occurs, the heart loses effective contraction for 4-15 seconds to have fainting and convulsions, the breathing slows down slowly, becomes shallow, so that the heart stops, the heart sounds disappear, the blood pressure can't reach, the skin appears purple, The pupils are scattered and the response to light disappears. Some patients can make abnormal snoring before death, but some can die quietly during sleep.

Examination of sudden cardiac death syndrome

First, patients with sudden cardiac death can generally check for obvious incentives:

1 External incentives include overwork, emotional agitation, alcoholism, and excessive smoking.

2 Intrinsic incentives include cardiac insufficiency, angina pectoris, and internal environment disorders.

Second, ECG examination

(1) Electrocardiogram examination, the following three performances can occur:

1 ventricular fibrillation (or flutter) wave pattern.

2 ventricular arrest, ECG straight line or only atrial wave.

3 ECG mechanical separation, ECG showed a slow deformed QRS wave, but did not produce effective myocardial mechanical contraction.

(2) Atypical ECG changes.

The main changes in early ECG are:

1 huge towering T wave, combined with clinical can make an early diagnosis.

2 Progressive ST segment changes, the early ST segment becomes straight, and the upward oblique elevation can reach 0. 1 mV or more), and the straight ST segment is connected to the towering T wave to form a so-called "high-sensitivity T wave", ST segment Progressive changes can develop into a one-way curve with the back of the bow.

3 Early QRS wave changes, due to the acute myocardial depolarization delay, "acute injury block", VA T 0. 45 seconds, QRS time limit can be extended to 0. 12 seconds, and often R wave amplitude increased, there are also significant depression .

Diagnosis and differentiation of sudden cardiac death syndrome

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

(1) Heart disease

Coronary heart disease is the most common cause of sudden death in the elderly. The literature shows that the average incidence of sudden death from coronary heart disease in China is 28.7/100,000, accounting for 45.1% of the total mortality of coronary heart disease. These deaths are often blocked by the trunk of the coronary artery or its branches. Usually, the emphasis is not enough or limited by medical conditions. Many people have not done an electrocardiogram or coronary angiography and have not been diagnosed. The disease has not been treated in a timely and effective manner, often after some large-scale myocardial infarction. It is easy to cause sudden death. In addition, other heart diseases, such as myocardial ischemia, aortic dissection, aortic stenosis, malignant arrhythmia, etc., are also the causes of sudden death.

(2) pulmonary embolism

Due to the continuous improvement of inspection methods, combined with the autopsy of the deceased, the incidence of pulmonary embolism has become more and more high in recent years, and it plays an important role in the cause of sudden death in the elderly. Because most of the elderly have hypercoagulable state, a considerable number of patients have Varicose veins of the lower extremities, phlebitis or thrombosis, some due to long bedtime, less activity, and prone to pulmonary embolism, once the blockage of the larger branch of the pulmonary artery, fatal consequences can occur, and the success rate of rescue is low.

(3) cerebrovascular disease

Mainly cerebral hemorrhage, the majority of patients with cerebral hemorrhage have the basis of vascular disease. Hypertension, diabetes and atherosclerosis are common causes. Under the emotional stimulation, alcohol and tobacco, etc., it can often cause a sharp rise in blood pressure. As a result, the blood vessels rupture and the amount of bleeding is less urgent to be sent to the hospital for treatment. It can save life. However, many patients have a large amount of bleeding, form cerebral palsy, oppress the life center, and will soon die. Therefore, when patients have headaches, nausea and other signs, Must pay attention to it.

(4) Digestive diseases

Hemorrhagic necrotizing pancreatitis leads to sudden death, and upper gastrointestinal bleeding can also cause sudden death. Patients with gastrointestinal bleeding often have potential esophageal varices, peptic ulcers, a large dose of medication or stress, and sudden bleeding at night. Causes shock or vomit to block the throat causing suffocation, etc., often the main cause of sudden death from upper gastrointestinal bleeding.

(5) hypoglycemia

Older diabetic patients are also more likely to die suddenly due to severe hypoglycemia at night. The reason is that a considerable number of elderly diabetic patients are not treated properly, or they are not eating in time after receiving hypoglycemic agents; some patients have large changes in blood glucose levels, often at night. Hypoglycemia occurs. Once severe hypoglycemia occurs, the vagal tone is too high due to inhibition of the central nervous system and sympathetic nervous system at night. If -blockers are used at the same time, the stress ability will be further reduced, and factors such as sleeping may often occur. Symptoms of typical hypoglycemia such as palpitation, hunger, and sweating can occur, and patients are less likely to be aware of them and cause sudden death.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.