sudden death
Introduction
Introduction Refers to a person who seems to be healthy in normal times, a sudden death due to a sudden onset or deterioration of a potential natural disease. A more accurate explanation is that if the organ is unbearable and dead, it is called sudden death. However, these organs are not necrotic. Necrosis is usually caused by injuries, while sudden death is caused by excessive use of strength, just like a computer that is overkill. Sudden death is a sudden and serious dysfunction of life organs such as B, brain, lungs, and even death caused by sudden suspension of activities.
Cause
Cause
Etiology classification
(a) heart disease
1. Coronary atherosclerotic heart disease.
2, acute myocarditis.
3, primary dilated cardiomyopathy, Keshan disease.
4, idiopathic hypertrophic aortic stenosis.
5, aortic stenosis.
6, pulmonary stenosis and tetralogy of Fallot.
7, acute heart tamponade, such as pericardial hemorrhage, heart rupture.
8, atrial new liquid tumor, balloon-like thrombus.
9, mitral valve prolapse.
10, idiopathic: QT interval prolongation syndrome with /X congenital deafness.
11, ventricular pre-excitation syndrome complicated by atrial fibrillation.
12, syphilitic heart disease with aortic valve insufficiency.
13, patients with primary pulmonary hypertension.
(B) macrovascular disease
1, pulmonary embolism.
2. Aortic aneurysm rupture.
3. Aortic dissection.
4, coronary aneurysm or arteriovenous thin rupture.
5, intracranial hemorrhage (hypertensive cerebral hemorrhage, intracranial aneurysm or cerebral arteriovenous malformation caused by subarachnoid hemorrhage.
6, the third ventricle gelatinous cyst.
7, ectopic pregnancy rupture, spontaneous spleen rupture caused by internal bleeding, gastrointestinal bleeding such as esophageal varices, ulcer bleeding.
(three) respiratory diseases
1, the respiratory tract attracts foreign bodies, throat sputum and so on.
2. Asthma persists.
3, acute respiratory paralysis, multiple radiculitis, poliomyelitis and so on.
(4) Electrolyte and acid-base balance disorder
1, hypokalemia.
2, high blood potassium.
3, low blood magnesium.
4, high blood calcium.
5, low blood calcium.
6, severe acidosis.
(5) Drug allergy, poisoning
1, anti-arrhythmia drug poisoning: digitalis, quinidine, procaine phenolamine, psoprolol, verapamil and so on.
2, anti-parasitic drug poisoning: bismuth potassium tartrate, ipecaine, chlorinated quinine, chlorpyrifos and so on.
3, Chinese medicine poisoning: an artemisia, aconite drugs.
4. Allergies to cyanine, streptomycin and serum preparations.
(6) Anesthesia and surgical accidents
1. Poor management of anesthesia and excessive secretion of respiratory tract.
2. Epidural anesthesia drugs are mistaken for the subarachnoid space.
3. The general anesthetic dose is too large and the muscle relaxant is not used properly. Local anesthesia accident, low temperature anesthesia, temperature is too low.
4, heart, abdominal surgery operation.
(7) Accidents caused by diagnostic operations or treatment
1, tracheal intubation, tracheotomy, bronchography, bronchoscopy.
2, gastroscopy.
3, pleural, pericardial puncture.
4. Compression of the carotid sinus.
5, cardiac catheterization, cardiovascular angiography, cerebral angiography and so on.
6. The pacemaker is set and faulty.
7, a large amount of cold blood infusion.
(8) Others
Acute pancreatitis, unexplained causes, etc.
mechanism
First, cardiac arrest
Cardiac arrest is a cardiac death and drug reaction, electrolyte imbalance, anesthesia accident. The common mechanism of falling to death during surgery is often characterized by transient death, which is caused by ventricular fibrillation or ventricular arrest caused by unstable ECG or ECG. Its pathophysiological mechanism is:
1 hypoxia: increased anaerobic metabolism under hypoxic conditions, accumulation of acidic metabolites and release of potassium ions, inhibiting myocardial contractility, self-discipline and conductivity, induced ventricular arrest; acute hypoxia can cause ECG instability It leads to rapid ventricular arrhythmia and ventricular fibrillation.
2 carbon dioxide retention and acidosis: asphyxiation caused by various causes can lead to carbon dioxide retention and respiratory acidosis, directly inhibit myocardial contractility and conductivity, or excite the heart inhibition center, causing bradycardia, but also because of high Blood potassium causes ventricular arrest.
3 autonomic dysfunction: excessive vagal tone can directly cause bradycardia or even ventricular arrest, or induce ventricular fibrillation through coronary artery spasm. Cardiac arrest can be caused by direct stimulation or reflex excitatory vagus nerve during surgery.
4 electrolyte disorder: hyperkalemia can inhibit the conduction and contractility of the heart, resulting in conduction block and ventricular arrest; hypokalemia enhances myocardial excitability and induces rapid ventricular arrhythmia and ventricular fibrillation. Hypocalcemia often coexists with hyperkalemia, which can aggravate the paralysis effect of hyperkalemia on the heart. The effect of magnesium on the heart is similar to that of blood potassium.
5 Electrophysiological abnormalities: Late studies have shown that ventricular repolarization caused by heterogeneity of ventricular repolarization is closely related to the occurrence of ventricular fibrillation. The electrocardiogram shows QT interval prolongation and u wave hyperplasia.
Second, acute cardiac bleeding is blocked
Sudden aorta, ventricular outflow tract or severe obstruction of the atrioventricular valve can cause sudden cardiac obstruction and death. The disease that causes sudden discharge of blood to the left ventricle is aortic stenosis. Idiopathic hypertrophic aortic stenosis, left atrial myxoma. Patients who have surgery or are in bed for a long time may develop pulmonary embolism due to deep venous thrombosis of the lower extremities, causing obstruction of right ventricular discharge and sudden death.
Third, acute pericardial tamponade
After acute myocardial infarction, cardiac rupture, aortic sinus aneurysm, syphilitic ascending aortic aneurysm and dissecting aneurysm rupture to the pericardium, causing acute cardiac tamponade and shock, and the patient may die immediately or within half an hour.
Fourth, shock
All types of shock can be killed. The mortality rate of cardiogenic shock after acute myocardial infarction is very high, and patients often die within 24 hours.
Fifth, the respiratory cycle central function damage.
Examine
an examination
Related inspection
Two-dimensional echocardiography Doppler echocardiography
First, medical history
The medical history is very important for the diagnosis of sudden death. From the onset of the attack to death within a few seconds or less, most of them are sudden cardiac death. Men over the age of 40 who are killed in public places or workplaces, regardless of the history of heart disease, should first consider the possibility of coronary heart disease. For patients with previous heart disease, if you have recent angina, syncope or severe arrhythmia, you should be alert to death. Female dying is less common, mostly caused by pulmonary hypertension. Most of the sudden death of infants and young children is caused by suffocation or congenital heart disease. Sudden death occurred during surgery or invasive examination, and cardiac arrest caused by excessive vagal tone is more common. Sudden cardiac arrest caused by drug allergy occurred within 15 minutes after injection of drugs such as cyanine and streptomycin. Sudden death from drug poisoning occurs mostly during intravenous injections using antiarrhythmic or antiparasitic drugs, or within hours of taking the drug.
Second, physical examination
The blood circulation stops immediately after the sudden death, and the body can be found. A series of symptoms and signs such as loss of consciousness, dilated pupils, disappearance of large arteries, blood pressure, respiratory arrest or intermittent.
Third, laboratory inspection
The blood acidity of patients with sudden death is increased. In addition, the biochemical examination of sudden death caused by electrolyte imbalance can find the corresponding causes: hypokalemia, hyperkalemia, and hypocalcemia.
Fourth, equipment inspection
The device examination of sudden death mainly relies on electrocardiogram, which not only can diagnose the cause, but also provide an important basis for cardiopulmonary resuscitation. There are three types of dying ECG charts:
1 ventricular fibrillation: the most common, especially in the first 4-6min of cardiac arrest, more common in coronary heart disease and other organic heart disease, hypokalemia, anesthesia accident, quinidine syncope, electric shock, heart surgery, Under the circumstances of drowning.
2 ventricular arrest: ECG is a straight line, mostly occurred in sick sinus syndrome, high atrioventricular block and high blood potassium. The continuation is often a dying performance, and the transient can occur after the application of P.C.
3 electro-mechanical separation: a slow and irregular ventricular arrhythmia or electro-peristaltic wave, more common in the end stage of organic heart pump failure, or myocardial infarction after heart rupture, recovery is often ineffective.
Diagnosis
Differential diagnosis
First, coronary atherosclerotic heart disease (coronary heart disease)
Coronary heart disease is the most common cause of sudden cardiac death, and more than 60% of patients have no history of coronary heart disease before sudden death. Generally seen in men over the age of 35-40, they are generally healthy, but have one or more predisposing factors such as hypertension, hyperlipidemia, and smoking. A small number of patients have a history of coronary heart disease before sudden death, such as frequent and exacerbated angina pectoris, electromyography found malignant arrhythmia, etc. For these aura symptoms, active measures should be taken to reduce the occurrence of sudden death. 20%-40% of patients with sudden death caused by coronary heart disease have an electrocardiogram showing myocardial infarction, which can be killed from several minutes to several hours after the onset, and the remaining 60%-80% of patients have sudden cardiac arrest. .
Second, myocarditis
Acute viral myocarditis is a common cause of sudden death in children and young people. The pathogenic viruses include Coxsackie A, B, Echo, and influenza viruses. The Coxsackie B virus has the most chance of invading the myocardium. Infants and young children are more likely to die than in the acute phase, while adults are mostly killed during the recovery period. Before the death, there are often systemic manifestations of viral infection such as fever, respiratory symptoms, body aches, etc. Cardiac examination may have diffuse myocardial damage such as enlarged heart, weakened myocardial activity and heart failure. Severe patients may have severe arrhythmia. Such as sick sinus syndrome, complete atrioventricular block and so on.
Third, primary cardiomyopathy
Sudden death caused by primary cardiomyopathy often has a family history, mainly with primary hypertrophic cardiomyopathy, and sudden death can occur in 10%-25%. More common in men, may have angina, syncope and other symptoms, the left sternal border or the apex of the apex often can be heard and contraction of the middle and late murmur, combined with isoamyl nitrite or isoproterenol after the murmur is louder. About 10% of patients with an electrocardiogram can find abnormal Q waves that resemble myocardial infarction. Echocardiography can show asymmetry of ventricular septal hypertrophy and reduced amplitude of contraction, which is a specific finding for the diagnosis of this disease.
Fourth, Keshan disease
Keshan disease is an endemic disease with epidemiological characteristics: the affected population are rural population, with obvious regional and seasonal characteristics. Northeast, Inner Mongolia, and Shaanxi are more common in winter, more common in women, and Sichuan and Anhui. Lu, and other places are more common in spring and summer, mainly in children. Can be manifested as cardiogenic shock or acute heart failure, heart enlargement and myocardial damage, more often preceded by rapid ventricular arrhythmia or complete atrioventricular block.
Five, aortic valve disease
(a) aortic stenosis
Most of the young patients have rheumatic aortic stenosis, often combined with aortic regurgitation or mitral stenosis, unless accompanied by rheumatic aortitis, less sudden death. Most elderly patients with simple aortic stenosis, often degenerative valvular sclerosing and calcification on congenital two-leaf or single-leaf aortic valve, patients often have a history of angina pectoris, aortic valve area can be heard And systolic murmur, X-ray examination showed left ventricular hypertrophy, electrocardiogram has severe intraventricular block.
(two) aortic valve insufficiency
Seen in syphilitic aortic valve insufficiency, especially those with angina pectoris, is prone to sudden death. More common in men over 40 years old, there is a sigh-like diastolic murmur in the aortic valve area, and the surrounding vascular signs are obvious. X-ray examination showed that the ascending aorta dilated and the left ventricle were significantly enlarged, and the heart shadow was huge like a boot. ECG has significant left ventricular hypertrophy and strain performance.
Sixth, idiopathic call duration extension syndrome
Most of the disease has a family history, often occurring in a family of several brothers and sisters, the main clinical features are congenital deafness, syncope, arrhythmia, sudden death. In normal ECG examination, it can be found that the T-wave width is notched, high-pointed, biphasic or inverted, and the repolarization of the u-wave is delayed. The first episode of the disease is common in young children, especially in infancy, and can continue to the first episode of 10-30 years old, which is one of the causes of sudden death for healthy children and young people, especially the important cause of sudden death in infants.
Seven, acute pancreatitis
Hemorrhagic necrotic pancreatitis in acute pancreatitis is an important disease that is younger and younger and is often misdiagnosed as acute myocardial infarction. Perforation of ulcer disease, acute cholecystitis, etc. A small number of patients who had been examined before birth had a history of angina pectoris, and more than half had ECG abnormalities such as premature beats, ST-T changes, and conduction block. Individual cases even showed myocardial infarction patterns. In order to reduce missed diagnosis, patients with acute abdomen should think about the possibility of this disease, and pay attention to the changes of ECG, and timely determine serum amylase. Positive positronbumin in chest and ascites or non-tip blood is one of the important indicators of the disease.
Eight, pulmonary embolism
Patients who have been bedridden after surgery or have been in bed for a long time have sudden breathing difficulties, coughing, irritability and rapid transfer to shock, hair group, coma, respiratory arrest and death, mostly due to pulmonary embolism. It is also common in the process of cardiovascular angiography, brain trauma, chest trauma and artificial pneumoperitoneum.
Nine, hypokalemia
Hyperkalemia causes sudden death, which is common in long-term fasting, massive fluid drainage, frequent vomiting or long-term use of potassium-sparing diuretics and large amounts of steroids, and certain drugs such as quinidine. Synergistic effects of digitalis and other drugs. Clinical manifestations are burnout and weakness. Bloating, sudden syncope, convulsions, etc. Electrocardiogram examination can be found in frequent or multi-source ventricular premature beats and short-ventricular tachycardia. Ventricular fibrillation can also have the performance of repolarization delay such as prolongation of interlobular phase, low wave or inversion of T wave, and huge u wave. Serum potassium concentrations can be as low as 1.5-2.5 mmol/L.
X. Hyperkalemia
Severe hyperkalemia caused by cardiac arrest is more common in severe hemolysis, large area crush injury, renal failure and oliguria, severe acidosis or long-term use of potassium-sparing diuretics alone. When the serum potassium concentration is as high as 7-8 mmlo/L, the early electrokinetic pattern can be expressed as a high-tipped and narrow tabular T wave, then the QRS complex is broadened, the heart rate is slowed down, and then the P wave disappears, and finally appears slowly and ineffective. The ventricular autonomic rhythm or ventricular arrest and death.
XI, drug poisoning or allergy
Drug poisoning such as tincture, chlorin, quinidine, and digitalis all cause sudden death with severe arrhythmia. Most of them cause ventricular fibrillation with malignant ventricular arrhythmia as a precursor, especially when the body is in hypokalemia. Cardiac arrest should occur in the process of rapid intravenous injection of phenytoin sodium, calcium chloride, aminophylline, etc., which should be taken seriously. Patients with sudden ventricular arrest during verapamil and Ptyrolol are more common in patients with low sinus node function. The use of cyanine, streptomycin and certain serum preparations may cause ventricular arrest due to an allergic reaction and sudden death.
