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Overview of Coronary Artery Disease (CAD)


The Manual's Editorial Staff

Reviewed/Revised Apr 2023
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What is coronary artery disease?

The heart is a muscle that pumps blood. Like all muscles, the heart needs a steady supply of blood to work. Blood that pumps through the heart doesn't feed the heart muscle. Instead the heart muscle is fed by its own arteries. These arteries are called coronary arteries.

Coronary artery disease (heart disease) happens when blood flow through the coronary arteries is partially or totally blocked.

Unstable angina and heart attack can cause an abnormal heart rhythm or cause your heart to stop. You can die if you aren't treated quickly. Also, a heart attack causes permanent heart damage.

Supplying the Heart With Blood

Like any other tissue in the body, the muscle of the heart must receive oxygen-rich blood and have waste products removed by the blood. The right coronary artery and the left coronary artery, which branch off the aorta just after it leaves the heart, deliver oxygen-rich blood to the heart muscle. The right coronary artery branches into the marginal artery and the posterior interventricular artery, located on the back surface of the heart. The left coronary artery (typically called the left main coronary artery) branches into the circumflex and the left anterior descending artery. The cardiac veins collect blood containing waste products from the heart muscle and empty it into a large vein on the back surface of the heart called the coronary sinus, which returns the blood to the right atrium.

Supplying the Heart With Blood

What causes coronary artery disease?

The most common cause of coronary artery disease is atherosclerosis Atherosclerosis In people with atherosclerosis, patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or blocked... read more Atherosclerosis , commonly known as hardening of the arteries. In atherosclerosis, cholesterol and other fatty material slowly build up in your arteries. This build-up is called an atheroma or plaque. The plaque may:

Fatty Deposits in a Coronary Artery

Less common causes include a sudden spasm of a coronary artery, usually from using illicit drugs such as cocaine. During a spasm, the artery suddenly squeezes shut. If it stays shut long enough, you can have a heart attack. Usually the spasm stops and the artery opens up again.

What are the risk factors for coronary artery disease?

How can doctors tell if I have coronary artery disease?

Your doctor will ask you questions about your symptoms and do a physical exam and blood tests.

If you have symptoms of a blocked artery, your doctor may do tests:

How do doctors treat coronary artery disease?

Doctors treat the problem that's causing your coronary artery disease, which is usually hardening of the arteries. They may:

  • Give you medicine to lower the workload on your heart, such as blood pressure medicine

  • Give you medicine to lower your cholesterol level

  • Ask you to change any unhealthy behaviors that may hurt your heart—for example, smoking, not exercising, and eating a poor diet

  • Sometimes do a procedure to open a blocked artery

Depending on how much your coronary arteries are blocked, doctors may do a procedure to clear your artery. They may do angioplasty or bypass surgery (also called coronary artery bypass grafting or coronary artery bypass surgery).

During angioplasty:

  • The doctor puts a small, flexible tube (catheter) into an artery in your upper leg (groin) or in your wrist

  • The catheter is pushed up the artery to your heart and then into one of your coronary arteries

  • A small balloon on the tip of the catheter is inflated

  • The balloon pushes the blockage open

  • Then the doctor slips a wire mesh tube (stent) off the end of the catheter into the blocked area

  • The wire mesh tube helps hold the blocked area open


During bypass surgery:

  • Doctors take a piece of healthy artery or vein from another part of your body

  • They sew one end of that piece of artery or vein to your aorta (the major artery that takes blood from your heart to the rest of your body)

  • They sew the other end to your blocked artery past the point of the blockage

  • Your blood then flows through this new route, bypassing the blockage

How can I prevent or reverse coronary artery disease?

Change behaviors that may hurt your heart

  • Stop smoking—this is the most important way to prevent or reverse coronary artery disease

  • Eat healthy foods, such as fresh fruits and vegetables and other high-fiber foods

  • Eat less fat from meats, dairy, and processed foods (such as frozen pizza or microwaveable dinners)—talk to your doctor about how much and which types of fat you should eat

  • Lose weight if you're overweight

  • Stay active by using weights or walking

  • Stop using illicit drugs—this can be hard to stop, so talk to your doctor or a counselor about how to get help

Take your medicines correctly

Drugs Mentioned In This Article

Generic Name Select Brand Names
Anacin Adult Low Strength, Aspergum, Aspir-Low, Aspirtab , Aspir-Trin , Bayer Advanced Aspirin, Bayer Aspirin, Bayer Aspirin Extra Strength, Bayer Aspirin Plus, Bayer Aspirin Regimen, Bayer Children's Aspirin, Bayer Extra Strength, Bayer Extra Strength Plus, Bayer Genuine Aspirin, Bayer Low Dose Aspirin Regimen, Bayer Womens Aspirin , BeneHealth Aspirin, Bufferin, Bufferin Extra Strength, Bufferin Low Dose, DURLAZA, Easprin , Ecotrin, Ecotrin Low Strength, Genacote, Halfprin, MiniPrin, St. Joseph Adult Low Strength, St. Joseph Aspirin, VAZALORE, Zero Order Release Aspirin, ZORprin
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