Coronary artery disease (CAD) is a condition in which plaque (plak) builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood.

Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis.

Plaque narrows the arteries and reduces blood flow to your heart muscle. It also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow.

Overview

When your coronary arteries are narrowed or blocked, oxygen-rich blood can't reach your heart muscle. This can cause angina or a heart attack.

Angina is chest pain or discomfort that occurs when not enough oxygen-rich blood is flowing to an area of your heart muscle. Angina may feel like pressure or squeezing in your chest. The pain also may occur in your shoulders, arms, neck, jaw, or back.

A heart attack occurs when blood flow to an area of your heart muscle is completely blocked. This prevents oxygen-rich blood from reaching that area of heart muscle and causes it to die. Without quick treatment, a heart attack can lead to serious problems and even death.

Over time, CAD can weaken the heart muscle and lead to heart failure and arrhythmias. Heart failure is a condition in which your heart can't pump enough blood throughout your body. Arrhythmias are problems with the speed or rhythm of your heartbeat.

Who is at risk for CAD?
Risk factors are conditions that increase your risk of developing heart disease. Some can be changed and some cannot. Although these factors each increase the risk of CAD, they do not describe all the causes of coronary heart disease; even with none of these risk factors, you might still develop CAD.

Controllable

• High blood pressure
• High blood cholesterol
• Smoking
• Obesity
• Physical inactivity
• Diabetes
• Stress

Uncontrollable

• Gender
• Heredity (family history of CAD)
• Age

Although stress may be a risk factor for CAD, scientists still do not know exactly how stress might be involved in heart disease.

What are the symptoms of CAD?

Chest pain (angina) or shortness of breath may be the earliest signs of CAD. A person may feel heaviness, tightness, pain, burning, pressure, or squeezing, usually behind the breastbone but sometimes also in the arms, neck, or jaws. These signs usually bring the patient to a doctor for the first time. Nevertheless, some people have heart attacks without ever having any of these symptoms.

It is important to know that there is a wide range of severity for CAD. Some people have no symptoms at all, some have mild intermittent chest pain, and some have more pronounced and steady pain. Still others have CHD that is severe enough to make normal everyday activities difficult.

Because CAD varies so much from one person to another, the way a doctor diagnoses and treats CHD will also vary a lot. The following descriptions are general guidelines to some tests and treatments that may or may not be used, depending on the individual case.

An examination for CAD may include the following tests:

An electrocardiogram (ECG or EKG) is a graphic record of the electrical activity of the heart as it contracts and rests. Abnormal heartbeats and some areas of damage, inadequate blood flow, and heart enlargement can be detected on the records.

A stress test (also called a treadmill test or exercise ECG) is used to record the heartbeat during exercise. This is done because some heart problems only show up when the heart is working hard. In the test, an ECG is done before, during, and after exercising on a treadmill; breathing rate and blood pressure may be measured as well. Exercise tests are useful but are not completely reliable; false positives (showing a problem where none exists) and false negatives (showing no problem when something is wrong) are fairly common.

Nuclear scanning is sometimes used to show damaged areas of the heart and expose problems with the heart's pumping action. A small amount of radioactive material is injected into a vein, usually in the arm. A scanning camera records the nuclear material that is taken up by heart muscle (healthy areas) or not taken up (damaged areas).

Coronary angiography (or arteriography) is a test used to explore the coronary arteries. A fine tube (catheter) is put into an artery of an arm or leg and passed through the tube into the arteries of the heart. The heart and blood vessels are then filmed while the heart pumps. The picture that is seen, called an angiogram or arteriogram, will show problems such as a blockage caused by atherosclerosis. 

Outlook

CAD is the most common type of heart disease. It's the leading cause of death in the United States for both men and women. Lifestyle changes, medicines, and/or medical procedures can effectively prevent or treat CAD in most people.