the difference between heart attack and cardiac arrest

Source: National Heart, Lung and Blood Institute

A heart attack occurs when blood vessels that supply blood to the heart are blocked, preventing enough oxygen from getting to the heart. If the blood supply is cut off for more than a few minutes, muscle cells suffer permanent injury and begin to die. This can kill or disable someone, depending on how much heart muscle is damaged.

Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, then the heart starves for oxygen and heart cells die. The medical term for heart attack is myocardial infarction.

Cardiac arrest is the sudden, abrupt loss of heart function. During cardiac arrest a victim loses consciousness, stops normal breathing, and loses pulse and blood pressure.

During cardiac arrest, people are less likely to die if they have early cardiopulmonary resuscitation (CPR) and defibrillation. Giving CPR keeps blood and oxygen flowing to the heart and brain until defibrillation can be administered. Defibrillation is delivering an electric shock to restore the heart rhythm to normal. Without proper medical attention, the person will die within a few minutes.

The heart has an internal electrical system that controls the rhythm of the heartbeat. Several problems can cause abnormal heart rhythms, called arrhythmias. During an arrhythmia, the heart can beat too fast, too slow, or it can stop beating. Sudden cardiac arrest occurs when the heart develops an arrhythmia that causes it to stop beating. This is different than a heart attack, where the heart usually continues to beat, but blood flow to the heart is blocked.

Steps to prevent heart attack and cardiac arrest:
- keep your weight in the normal range.
- see your doctor for regular check-ups.
- treat high blood pressure, if you have it.
- control high blood cholesterol, if you have it.
- have your cholesterol levels checked once a year.
- control your blood sugar level if you have diabetes.
- have your blood pressure checked on a regular basis.
- exercise at least 30 minutes on most days of the week.
- eat a diet high in fiber with lots of fresh fruits and vegetables.
- eat a diet low in saturated fat, trans fat, cholesterol, salt or sodium.
- remember that excessive alcohol use increases the risk of high blood pressure, heart attack, and stroke.
- do not smoke. Also, exposure to other people's smoke can increase the risk of heart disease even for nonsmokers.