Initial Treatment for Heart Attack
The goals of initial treatment are to minimize damage by restoring blood flow to the heart and to determine the amount of damage to heart tissue. It is critical to call for immediate medical attention (i.e., call 9-1-1) if heart attack is suspected.Intensive research over the last 20 or more years has demonstrated that prompt treatment can decrease damage from a heart attack and increase the chance for survival.
The heart may develop irregular heart rhythms (arrhythmias) or stop beating (sudden cardiac arrest) during a heart attack. When the heart is unable to pump blood throughout the body, brain damage and death can occur within minutes.
Emergency medical personnel can quickly assess the situation and may perform an electrocardiogram (ECG) to measure electrical activity in the heart. If the patient is in cardiac arrest, or is experiencing an abnormal heart rhythm, a device called a defibrillator may be used to "shock" the heart into a normal rhythm.
Emergency medical personnel also can administer medications and begin treatments immediately that can help dissolve a blood clot and open a blocked coronary artery, restoring normal blood flow to the heart. If these therapies are initiated within 1 hour of the onset of symptoms, less irreparable damage may occur.
Even before emergency personnel arrive, cardiopulmonary resuscitation (CPR) can be performed if the patient has no pulse and a capable bystander is present. CPR is a combination of chest compressions and rescue breathing. Automated external defibrillators designed for CPR are available in some public places (e.g., airports, shopping malls, large office buildings). Defibrillators also are available without a prescription for home use.
In October 2010, the American Heart Association (AHA) released updated guidelines for performing cardiopulmonary resuscitation. The new CPR guidelines, which are applicable for adults and children 3 months of age and older, involve chest compressions at the rate of at least 100 per minute.
The three basic parts of the new CPR procedure are referred to as the "CAB sequence." The letters C-A-B stand for the following:
- Circulation (Chest Compressions)
- Airway (Clear the Airway)
- Breathing (Perform Rescue Breathing, also called Mouth-to-Mouth Resuscitation)
Recent studies have shown that a procedure called cardiocerebral resuscitation may help improve outcomes for patients who suffer a heart attack outside of a hospital setting. In cardiocerebral resuscitation, emergency personal administer uninterrupted chest compressions for approximately 2 minutes (200 compressions), then perform regular CPR and use a defibrillator to administer an electrical shock, if necessary.
If the patient is still in cardiac arrest, the procedure is repeated as many as 3 times. Cardiocerebral resuscitation also involves administering epinephrine (drug that constricts blood vessels) as quickly as possible and with each cycle of 200 chest compressions.
Studies have shown that cooling the body temperature to between 89.6 °F and 93.2 °F may help to prevent brain damage in patients who survive cardiac arrest lasting more than a few minutes. This treatment, which is called mild therapeutic hypothermia, should be started as soon as possible after the patient is resuscitated and continued for 12–24 hours. Cooling blankets, ice packs, fanning, and intravenous (IV) solutions can be used to lower the patient's core body temperature.