What causes cardiac arrest?

Cardiac arrest refers to the sudden cessation of heartbeats, leading to a drastic decline in blood circulation and the inability of blood to effectively deliver oxygen to brain tissue and other organs, thus triggering a severe life-threatening situation. The main causes may include: 1. **Heart diseases**: Such as myocardial infarction, coronary heart disease, and myocarditis. These conditions may lead to coronary artery atherosclerosis, myocardial ischemia and hypoxia, subsequently causing arrhythmias, and eventually resulting in cardiac arrest. 2. **Chronic hypoxia**: Certain lung diseases, such as emphysema and pulmonary heart disease, if not treated promptly, may lead to chronic hypoxia, which can endanger life. 3. **Electrolyte imbalance**: Severe vomiting, diarrhea, and similar conditions may induce electrolyte disturbances and acid-base imbalance, leading to physical weakness and loss of circulatory function, potentially resulting in cardiac arrest. During cardiac arrest, patients may exhibit signs such as cessation of blood circulation, disappearance of heart sounds, absence of arterial pulses, and unmeasurable blood pressure. Additional symptoms may include gasping respiration or respiratory arrest, dilated pupils, and cyanosis of the skin and mucous membranes. When encountering a patient experiencing cardiac arrest, immediately call emergency services and administer first aid measures such as cardiopulmonary resuscitation (CPR) to attempt to save the patient's life.