Overview
Sudden death coronary artery disease is defined as the sudden death of a person with no history of heart disease or only mild symptoms of heart disease, who is basically in stable condition, and who dies suddenly due to myocardial failure or mechanical failure in which the heart loses its effective contraction, without any obvious external cause, not trauma, and not self-inflicted injury. The time from sudden onset of symptoms to death varies. The American Institute of Hematology sets the time at 24 hours, the World Health Organization sets the time at 6 hours, and cardiologists define death within 1 hour of onset as sudden death.
Causes
1. Physical exertion: over fatigue from previous strenuous and prolonged labor.
2. Satiety, alcohol consumption and excessive smoking.
3. Over-excitement and agitation of mental nerves.
4. Severe cardiac insufficiency: unstable angina.
5. Hypokalemia and hypomagnesemia.
6. Certain antiarrhythmic drugs.
Symptoms
Only 12% of sudden cardiac deaths are preceded by a visit to the doctor for a cardiac condition in the 6 months prior to death. The vast majority of patients are overlooked because of the lack of specificity of symptoms.
1. self-induced chest pain or angina pectoris of a changed nature with dyspnea days or weeks before the onset of the disease.
2. Tiredness and weakness in the days or weeks before sudden cardiac death are common symptoms.
3. specific cardiac symptoms persistent angina pectoris arrhythmia, heart failure, etc.
4. Mostly occurs in winter, half of the patients do not have a little symptom before the onset of the disease.
5. The performance of cardiac arrest:
(1) sudden loss of consciousness often or convulsions can be accompanied by convulsions;
(2) disappearance of large artery (carotid femoral artery) pulsation;
(3) Loss of heart sounds on auscultation;
(4) Sighing respiration or respiratory arrest with cyanosis;
(5) Dilated pupils and cyanosis of the mucous membranes and skin.
(6) No more bleeding from the wound at the time of surgery.
Examination
Metabolic acidosis due to hypoxia, decrease in blood pH; increase in blood glucose and amylase may occur.
1. Electrocardiography
(1) Ventricular fibrillation (or flutter) Presents ventricular fibrillation wave or flutter wave, which accounts for about 80% of the cases, and the success rate of resuscitation is the highest.
(2) Ventricular arrest The ECG shows a straight line or only atrial waves.
(3) Electrocardiographic-mechanical separation Although there is a slow and wide QRS wave on the ECG, it cannot produce an effective mechanical contraction of the heart.
2. Electroencephalography
The brain waves are low and flat.
Diagnosis
With reference to the relevant standards at home and abroad, any person who meets one of the following conditions can be diagnosed as sudden coronary death:
1. Sudden onset of angina pectoris and death within 6 hours or during sleep after having been diagnosed with coronary heart disease or suspected coronary heart disease in the past.
2. sudden onset of angina pectoris or cardiogenic shock, ECG shows acute myocardial infarction or aura of infarction, and death within 6 hours.
3. sudden death with significant coronary atherosclerosis confirmed by autopsy. Since the direct cause of sudden coronary death is mostly due to ventricular fibrillation, and the electrophysiological basis of ventricular fibrillation is ventricular myoelectric instability, the prevention of sudden coronary death is mainly to predict the occurrence of ventricular fibrillation.
Treatment
Timely treatment of patients with coronary heart disease, especially for the timely detection of arrhythmias that may evolve into sudden cardiac arrest, such as the timely treatment of patients with coronary heart disease, especially for the timely detection of arrhythmias that may evolve into sudden cardiac arrest. Once a patient dies suddenly, cardiopulmonary brain resuscitation (CPR) should be performed immediately.
Cardiopulmonary resuscitation, whether it is any cause of cardiac arrest or sudden cardiac death, once found should be immediately rescued, due to sudden death except for a small portion of the occurrence of hospitals, most of the out-of-hospital, and therefore the most important rescue resuscitation in the sudden death of the first 2 ~ 4min, to give a reasonable base of life support, the resuscitation can be successful, the key to whether the timely and correct to make judgments and implementation of the scene of rescue, the purpose of the recovery must be to achieve cerebral function, and the brain must be able to recover. The purpose of resuscitation must be to achieve the recovery of brain function.
1. Initial resuscitation or basic life support (BLS): the purpose of artificial respiration and artificial chest compressions is to establish effective oxygenated blood circulation under artificial conditions as soon as possible, to maintain the blood supply to the brain, to maintain basic life activities, and to create conditions for the next step of resuscitation, and it is proved by clinical practice that chest compressions should be carried out before artificial respiration.
(1) Establishment of artificial circulation: this period is mostly administered by eyewitnesses at the scene of the incident, so the knowledge of rescue should be popularized among the general public, so that a large number of people can understand and master the correct operation method, which is crucial for improving the success rate of resuscitation.
(1) Anterior heart area percussion: the rescuer makes a fist with one hand and gives a quick blow to the lower middle part of the patient’s sternum with the base of the ulnar side from a height of 20cm, if it is ineffective, then chest heart compression will be performed as soon as possible.
2) Thoracic cardiac compression: the correct method is:
a. The patient lies supine on a hardboard bed or on the ground, and the rescuer is located on the patient’s right side;
b. The rescuer crosses his/her hands and places the root of the palm of the hand at the junction of the middle and lower 1/3 of the patient’s sternum or the midpoint of the line between the two nipples;
c. Pressure on both sides of the arm should be straight, straight up and down uniform pressure and relaxation, relaxation of the palm of the hand does not leave the patient, the pressure to be able to make the lower part of the sternum and the connecting costal cartilage subsidence of 5cm is appropriate, children should be one-handed pressure, infants with the thumb, infants and young children with a high location of the heart should be pressed in the middle of the sternum, so as to avoid damage to the liver;
d. The frequency of pressing is more than 100 times/minute, and each pressing lasts for 0.5 seconds before relaxing.
Precautions: the force should not be too much to prevent rib fracture, pericardial hemorrhage and liver rupture, etc.; the compression should be continued and interruptions should be avoided as much as possible; thoracic cardiac compression should be carried out at the same time with artificial respiration, and the ratio of compression and respiration should be 30:2.
(2) Ensure airway patency: the jaw muscle of sudden death is flaccid, and the root of the tongue falls down, which is easy to block the airway. In order to keep the airway open, the patient’s head should be suppressed and the chin lifted, so that the patient’s oral axis and pharyngeal axis become a straight line, which can prevent the root of the tongue from falling down, and also facilitate tracheal intubation; at the same time, foreign objects and vomitus in the airway should be removed.
(3) Artificial respiration: While performing chest compressions to maintain blood circulation, if the patient is not breathing on his own, artificial respiration must be performed to ensure the input of oxygen and the discharge of carbon dioxide.
Mouth-to-mouth artificial respiration: the patient can get good alveolar ventilation, with the thumb and forefinger clamping the patient’s nose, so that it is tightly closed; the operator takes a deep breath, with lips tightly pressed against the patient’s mouth (in order to prevent contamination, but also can be covered with a layer of gauze on the patient’s mouth, etc.), blowing fully forcefully, the beginning of blowing should be 2 consecutive times to facilitate lung expansion, each time blowing into the gas 800 to 1200 ml, the blowing duration 1 to 1.5 s, each blowing duration 1 ~ 1.5 s, each time blowing to facilitate pulmonary expansion, each time blowing into the gas. 1.5s, after each blow, relax the patient’s nostrils, and use the natural retraction force of the chest and lungs to expel the gas, 12-15 times/minute.
2. Phase II resuscitation or further life support (ALS): mainly includes CPR procedures D, E, F, G, H. These measures should be started as early as possible, and if possible, should be carried out at the same time as phase I BLS, and strive to start within 8 min after sudden death, with the aim of promoting cardiac recovery.
3. Late resuscitation or continuous life support: after the timely treatment in the above two phases, the heart beat is recovered but the brain function is not yet fully recovered, in this phase, post-resuscitation life support must be carried out, i.e., late resuscitation focusing on brain resuscitation and further treatment of the original disease and comorbidities, in order to strive for the patient’s recovery.
Prevention
1. Carry out primary prevention of coronary heart disease in high-risk groups.
2. Strengthen the education of first aid knowledge at the scene of sudden death and establish a perfect first aid system.