Within 4 minutes of cardiac arrest is the prime time for resuscitation; beyond 4 minutes there is a risk of irreversible brain damage, and longer cardiac arrests result in brain death. Cardiopulmonary resuscitation, intravenous antihypertensive drugs, or epinephrine and pacemakers will not be very effective and usually have no chance of survival. Because heart attack is usually caused by a lesion in the internal blood vessels of the heart, the heart is the body’s blood pump that supports the circulation of blood throughout the body, resulting in the loss or complete loss of heart function. Once the heart stops, various organs and tissues throughout the body will experience different degrees of ischemia, which in turn will cause dysfunction of various organs and tissues in the body, and different degrees of damage and necrosis, and the chances of successful resuscitation due to respiratory arrest caused by heart attack are low.