CAD is damage or disease of the arteries that supply the heart muscle with blood. Changes to the blood vessel make it difficult for blood to flow, and slows or stops the delivery of nutrients and oxygen to the heart muscle.

Regular blood flow is needed through the coronary arteries to bring oxygen and nutrients to the constantly working heart muscle. Slowed or interrupted blood flow can cause damage to the heart muscle and decrease the heart’s ability to pump blood to the body. Blood flow that is less than needed is known as ischemia. Slowed blood flow to the heart can cause pain known as angina. When blood flow is completely cut off a myocardial infarction, commonly known as a heart attack, will occur.

CAD is the most common life-threatening disease in the United States.

Atherosclerosis is the most common cause of CAD. It is the narrowing of blood vessels due to a build up of a waxy substance, called plaque, on the walls of the blood vessels. The plaque is made in reaction to injury of the blood vessel walls and/or from substances in the blood. Patches develop over areas of injury on the blood vessel walls to help them heal. Substances in the blood like LDL “bad” cholesterol and glucose can get trapped in these patches and remain even after the injury has healed. Over time, more substances can get trapped in this patch and form plaque. The plaque is irritating to the blood vessel walls which causes more injury and creates a cycle that develops more plaque. The plaque growth continues to narrow the blood vessel opening.

Damage to blood vessels can occur from multiple factors such as:

• High blood pressure —causes turbulent blood flow that can injure the walls of blood vessels
• High cholesterol —”bad” cholesterol can stick to and irritate the walls of the blood vessels
• Diabetes —excess glucose in the blood can contribute to plaque build up in blood vessels
• Smoking —chemicals from cigarette smoke can irritate blood vessel walls and make deposits in the walls of blood vessels
• Radiation therapy

Coronary artery disease (CAD). EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated December 16, 2013. Accessed January 27, 2014.

What is coronary heart disease? National Heart, Lung, and Blood Institute website. Available at:
http://www.nhlbi.nih.gov/health/health-topics/topics/cad
Updated August 23, 2012. Accessed January 27, 2014.