Conditions InDepth: Coronary Artery Disease (CAD)

Coronary Artery Disease (CAD)

The coronary arteries supply blood to the heart muscle. CAD is damage or disease of these arteries. These changes slow or stop the flow of blood.

Regular blood flow is needed to bring oxygen and nutrients to the heart muscle. Without this supply the heart muscle cannot work well. A lack of oxygen can also lead to damage or death of heart muscle. Blood flow changes can lead to:

  • Ischemia—damage to heart tissue.
  • Angina—Chest pain caused by slowed blood flow to the heart. For some this may feel like a pressure or even shortness of breath.
  • Myocardial infarction —blood flow is completely cut off. Also called heart attack.

CAD is the most common life-threatening disease in the US.

CAD Causes

A narrowing of the blood vessels called atherosclerosis is the most common cause of CAD. This is a buildup of plaque on the walls of the blood vessels. The plaque begins because of:

  • Injury to the blood vessel walls
  • Substances in the blood that stick to walls

After an injury tissue collects or is deposited at the site. This helps the blood vessel heal. However, it can also make it easier for substances in the blood to stick to the area. Substances may include LDL "bad" cholesterol and cells linked to inflammation. They can remain even after the injury has healed. Over time, more substances can get trapped. Together they form plaque. The plaque irritates the blood vessel walls. This causes more injury and creates a new cycle that develops more plaque. The blood vessel opening gets more narrow with each layer of plaque. Damage to blood vessels can occur from multiple factors such as:

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

  • High blood pressure —causes rough 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 add 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

Blocked Coronary Artery

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Angina (chest pain). American Heart Association website. Available at:
...(Click grey area to select URL)
Updated December 14, 2017. Accessed March 5, 2018.
Coronary artery disease (CAD). EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated February 28, 2018. Accessed March 5, 2018.
Coronary heart disease. National Heart, Lung, and Blood Institute website. Available at: Accessed March 5, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board Michael J. Fucci, DO, FACC
Last Updated: 3/15/2015

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