Myocardial Infarction (Heart Attack)

What Is a Myocardial Infarction?
A myocardial infarction (MI) is the medical term for a heart attack. "Myocardia" refers to the heart muscle. "Infarction" causes permanent damage to a portion of the heart and results from a lack of oxygen and blood to an area of the heart.

Heart attacks are one of the most common illnesses that affect women and men of all age groups. Heart attacks are the leading cause of death in the United States.

How Does Your Heart Muscle Work?
Your heart is a strong muscle about the size of your clenched fist. Its job is to pump blood, oxygen, and nutrients to all parts of your body.

The right side of your heart pumps only the blood into your lungs. The left side of your heart must pump blood to all other parts of your body.

For the heart muscle to work, it needs oxygen and nutrients, which are delivered through the coronary (heart) arteries. There are two major coronary arteries:

• The right coronary artery (RCA) delivers blood to the right side and the back wall of your heart.
• The left coronary artery (LCA) splits into two branches: the circumflex artery (CFX) and the left anterior descending (LAD) artery which supply blood to the left side and middle walls of your heart. (See diagram.)

How Do Blockages Develop in Your Heart?
Over many years, the coronary arteries can gradually develop atherosclerosis ("hardening of the arteries"), which causes a thickening and hardening of the walls of the arteries. This process begins with the deposit of fatty materials, called plaque, on the inner lining of these arterial walls. As more of these deposits are formed and increase in size, they narrow the channel through which the blood flows. When a coronary artery has become so narrowed that blood flow is cut off, a part of the heart muscle may die. This is a myocardial infarction (MI), sometimes called a heart attack.

What Are the Signals of a Heart Attack?
Everyone will experience DIFFERENT symptoms with each heart attack. Symptoms that you MAY experience can include the following:

• a sensation in the chest that may be felt as choking, numbness, squeezing or pressure;
• a fullness or pain in the center of the chest behind the breastbone. These symptoms or sensations MAY extend to your jaw, neck, arms, or shoulder blades.

What Is the Difference Between a Heart Attack and Angina?
Angina is a temporary pain or tightness that may start in the chest and will sometimes spread to other parts of your upper body. It may start suddenly and last only a few minutes or longer. Angina will be relieved either by resting or taking nitroglycerin. A heart attack will not be relieved by rest or medication. If you suspect a heart attack, immediate medical attention is necessary!