A heart attack is an event that results in permanent heart damage or death. It is also known as a myocardial infarction, because part of the heart muscle (myocardium) may literally die (infarction). A heart attack occurs when one of the coronary arteries becomes severely or totally blocked, usually by a blood clot. When the heart muscle does not obtain the oxygen-rich blood that it needs, it will begin to die. The severity of a heart attack usually depends on how much of the heart muscle is Injured or dies during the heart attack.

Someone's chance of surviving a heart attack depends on the treatment that is given within the first hour of the heart attack. Immediate treatment for a heart attack should always include professional emergency medical intervention, including a call to 911 if the patient lives in an area with such access. While waiting for help to arrive or on the way to the hospital, patients are often told to begin chewing aspirin, a known blood clot inhibitor. It is thought that taking aspirin while experiencing a heart attack can decrease the risk of death by about 25 percent.

The preferred treatment of choice for a heart attack is Balloon Angioplasty with Stenting. The quicker the patient is able to get to a facility with angioplasty the better the chance the heart suffers less damage

The American Heart Association estimates that in 2001, more than 1 million Americans will suffer a coronary event, such as a heart attack or cardiac arrest. About 650,000 of these will be first-time attacks while about 450,000 will be recurrent attacks.