About the Heart --> Heart Disease --> Causes and Risks for Heart Disease

Most heart attacks are caused by a clot that blocks one or more of the coronary arteries (the blood vessels that bring blood and oxygen to the heart muscle). The clot usually forms in a coronary artery that has been narrowed over the years by a buildup of fat, cholesterol, and other deposits (plaques). This change in the arteries throughout the body is called atherosclerosis. When coronary arteries narrow due to atherosclerosis, the condition is known as coronary artery disease.

The clot in the coronary artery stops the flow of blood and oxygen to the heart muscle, leading to the death of heart cells in that area. The damaged heart muscle loses its ability to contract, and the remaining heart muscle must work harder to make up for it.

A heart attack can also occur when a blood clot from inside a diseased heart breaks loose and lodges in a healthy or narrowed coronary artery. Another rare cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to a part of the heart muscle. Drugs such as cocaine can cause such a life-threatening spasm.

The technical term for a heart attack is myocardial infarction. Like any muscle, the heart needs a steady supply of blood, or the tissue will be damaged or begin to die. Without blood, heart cells are injured, causing pain or pressure. If blood flow isn't restored, heart cells can die and scar tissue can form, replacing working heart tissue. If damage occurs to a large area of heart muscle, a heart attack can be fatal.
A heart attack is not a static one-time event. It is an active process that often occurs over 4 to 6 hours. With each passing minute, more heart tissue is deprived of blood and is damaged or dies. However, if blood flow can be restored in time, damage to the heart can be limited or prevented.

The risk factors for coronary artery disease and heart attack include:

• Smoking
  
• Hypertension (high blood pressure)
  
• High-fat diet
  
• High blood cholesterol (LDL) levels
• Diabetes
  
• Male gender
  
• Women post menopause
  
• Age
  
• Heart disease in family members before age 65.
  
• Obesity
  
• Physical Inactivity