Heart Attack (Myocardial Infarction)


A heart attack, also called a myocardial infarction (or MI), is a disruption of blood flow through one or more coronary arteries. These are the arteries that provide blood to the heart muscle. A heart attack can damage or kill the tissue of the heart. A heart attack can strike suddenly, often without any warning.


A heart attack occurs when a coronary artery becomes blocked. Usually, this is linked to a gradual process called atherosclerosis. Atherosclerosis is a buildup of thick, fatty plaque in the arteries. It causes the arteries to narrow and harden. When this happens in the coronary arteries, it is called coronary artery disease. Most heart attacks are caused by coronary artery disease.

Once a coronary artery becomes narrowed it is susceptible to blockage by a blood clot. A blood clot that forms within a narrowed artery is called a thrombus. Another type of clot, called an embolus, is a clot that has broken away from unstable plaque and traveled through the circulatory system. Both types of clots can become wedged in a narrowed coronary artery, stopping the flow of blood. When this happens, the heart muscle beyond the blockage is deprived of vital oxygen- and nutrient-rich blood. Within minutes, the heart muscle begins to deteriorate or die. This is a heart attack.


The classic symptom of a heart attack is chest pain. This pain is usually described as a pressing or squeezing sensation on the chest. In many cases this pain is felt during strenuous activity, but it may also occur during rest. It can last from several minutes to hours. Other symptoms may include pain in the shoulder, arm, back, neck, or jaw, shortness of breath, nausea and fatigue. The person may sweat and feel lightheaded.


Heart attacks strike both men and women. However, women often experience symptoms that are different from the classic symptoms of a heart attack. Many women do not have chest pain. Instead, they have shortness of breath, weakness, and fatigue. Their symptoms may be overlooked or misidentified. A person who experiences symptoms of a heart attack should seek treatment immediately.


During a heart attack, time is crucial. If blood flow can be restored quickly, damage can often be limited. A person who has a heart attack may be treated with a variety of options. These may include medications, coronary angioplasty, coronary stenting or bypass surgery.


A person can lower the risk of heart attack by eating a healthy diet and maintaining a healthy weight. Controlling cholesterol, minimizing stress, refraining from smoking and getting regular exercise are very important. A physician may prescribe medications to thin the blood, lower cholesterol and help the heart function more efficiently.