Cardiovascular emergency rescue guidelines: emergency treatment for cardiac arrest, early treatment of myocardial infarction and contraindications for medication.

Cardiac arrest is the most common cause of death. Knowing first aid can save a patient's life. If a patient is found in cardiac arrest, immediate on-site resuscitation is necessary; do not move them. First, perform precordial percussion. Make a fist with your right hand and strike the precordial area with moderate force 3-5 times. This should restart the heartbeat. If ineffective, immediately begin chest compressions. Immediately place the patient supine on a hard surface. Place your right palm on the lower third of the patient's sternum, and your left hand on the back of your right hand. Use the weight of your body and upper limbs to rhythmically and quickly compress the sternum vertically, depressing it 3-4 centimeters, then release. Repeat this 60-80 times per minute. When compressions are effective, a major artery pulse should be palpable, and systolic blood pressure should be maintained above 8 kPa (60 mmHg). Simultaneously with chest compressions, immediately begin mouth-to-mouth resuscitation. The operator uses one hand to pull the patient's jaw downwards to open their mouth, while the other hand tightly closes the patient's nostrils to prevent air leakage. Forcefully blow air into the patient's mouth, then use the lungs' recoil to induce exhalation. The blowing rate should be 12-16 breaths per minute, or one mouth-to-mouth breath for every four chest compressions. Simultaneously, contact the nearest hospital immediately for emergency treatment. In treating angina, the use of vasodilators is natural. However, coronary heart disease patients typically have a long disease course, and angina attacks do not disappear within a few years. Commonly used vasodilators include nitroglycerin, isosorbide dinitrate, and long-acting nitroglycerin. In recent years, many experts have pointed out that nitrate vasodilators sometimes exhibit "rapid tolerance" and are not suitable for long-term continuous use; intermittent use is preferred. Clinically, most angina attacks are sporadic, lasting only a few minutes, and timely application of nitrate vasodilators can immediately relieve symptoms; therefore, long-term use is not necessary. For patients with frequent angina attacks, continuous intravenous nitroglycerin infusion can be administered for a short period, or it can be considered to alternate with other medications. For those with frequent angina attacks, diltiazem (Dilthiazine) can be used, as it is less likely to cause drug tolerance. If angina attacks cannot be completely controlled during medication, adding nitrate vasodilators can achieve better results. Currently, many vasodilators have a long duration of action in the body; some long-acting preparations can be selected to alleviate patient suffering. However, for patients with frequent angina attacks due to acute myocardial infarction, long-term continuous use is generally not advisable. Acute myocardial infarction is a partial ischemic necrosis of the myocardium caused by sudden or near-blockage of the coronary arteries. It has been reported that 40%–60% of deaths from acute myocardial infarction occur before reaching the hospital, with most patients dying within one hour of symptom onset. Therefore, early treatment of acute myocardial infarction is crucial. After the onset of the disease, the patient should be kept in bed to reduce the workload of the heart and myocardial oxygen consumption, which can significantly reduce the area of ​​myocardial damage. Immediate oxygen inhalation should be administered. Effective pain relief should be provided to alleviate the patient's main pain and anxiety, often via intramuscular injection of pethidine, papaverine, or morphine. Close monitoring of pulse, heart rate, heart rhythm, and blood pressure is essential; continuous electrocardiogram monitoring should be implemented if possible. An intravenous access should be established to ensure timely intravenous medication, and a simultaneous defibrillator and emergency medications should be readily available. Appropriate indications should be selected; if conditions permit, intravenous thrombolysis with urokinase should be administered before hospitalization to reduce the size of the myocardial infarction and decrease complications. For patients with acute myocardial infarction, when the condition is basically stable, or when there are various serious complications making continued on-site resuscitation difficult and dangerous, the patient should be transferred to a hospital immediately. The following conditions should be considered when transferring a patient: pain has stopped, or has subsided after medication; blood pressure is normal, or has stabilized after medication; there are no serious arrhythmias, or they have stabilized after medication; there is no heart failure, or heart failure is basically under control. Before a patient is transferred, thorough medical arrangements are generally required. Intravenous fluids and continuous oxygen supply must be maintained during transport, and emergency medical support should be in place to prepare for necessary resuscitation efforts during transit.