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Coronary Artery Disease

What is coronary artery disease?
What are the symptoms of coronary artery disease?
What causes coronary artery disease?
How is coronary artery disease diagnosed?
How can coronary artery disease be treated?

What is coronary artery disease?

Coronary artery disease (CAD), also known as coronary heart disease or hardening of the arteries, means the arteries that supply your heart with blood have become narrowed due to plaque deposits and so are unable to keep up with its demands.

Your heart—a muscular organ that pumps, on average, five to six quarts of blood a minute—has a huge need for oxygen- and nutrient-rich blood. As blood is pumped out of the heart and into the aorta, some of it is channeled back to the heart itself, via the coronary arteries. These arteries start out as two major vessels on the surface of the heart that then branch out and penetrate the heart to supply it with oxygen and nutrients. When the workload of the heart increases with exertion and other stresses, so, too, does its need for oxygen-rich blood. A healthy heart can handle this increased demand. But a heart whose blood supply has been compromised by the development of CAD cannot keep up with the demand.

CAD is caused by atherosclerosis in the coronary arteries. Atherosclerosis is the progressive buildup of plaque, or deposits of cholesterol, inflammatory cells and other substances on the arterial walls; this buildup occurs over a period of years or even decades. As a result, the coronary arteries narrow, reducing their ability to carry blood. Moreover, atherosclerosis leads to a loss of the arteries' ability to dilate, or expand, in response to exercise; this process is sometimes called "hardening of the arteries.

Atherosclerosis can affect the arteries in any part of your body, but it has especially devastating consequences when it affects your coronary arteries: It can trigger angina, a condition characterized by chest pain—or a sensation of discomfort in the chest—due to an insufficient supply of blood to the heart. If the athersclerosis results in a complete blockage of the coronary artery, it will cause a heart attack (also known as a myocardial infarction). It can trigger an arrhythmia, a disturbance of your heart's rhythm. It can compromise your heart's ability to pump as strongly as it should, which can lead over time to the development of a condition known as congestive heart failure. And it can result in the formation of blood clots in the larger arteries of the body which, if they break loose and travel through your circulatory system, can lodge in your brain and cause a stroke.

CAD is the most common kind of heart disease in the U.S. and is the leading cause of death among both men and women; about 375,000 Americans die every year from CAD, according to the National Institutes of Health.

What are the symptoms of coronary artery disease?

Symptoms of a disease are indications that can be detected by the patient, such as pain or fatigue (while signs are indications that can be detected by a doctor, such as the results of a blood test or an X-ray).

The symptoms of CAD typically develop slowly, sometimes over a period of many years. Their severity can vary widely; in some cases, an individual with CAD may not feel any symptoms until the occurrence of a heart attack.

When symptoms do occur, the most common one is angina, a sensation of pain or pressure in your chest, left arm or jaw. Other common symptoms of CAD include trouble breathing, even when lying flat, and swelling in your feet, ankles, legs, and abdomen and in the veins of your neck; these symptoms are all caused by a buildup of fluid in your body and can eventually result in congestive heart failure.

Other symptoms that may signal the presence of CAD include nausea or vomiting; lightheadedness or fainting; insomnia (trouble sleeping); fatigue or lack of energy; loss of appetite or a feeling of indigestion; clammy skin; a fast or irregular heartbeat; and palpitations (a fluttering sensation in your heart).

What causes coronary artery disease?

Researchers are still studying the exact mechanisms of the atherosclerosis that results in the development of CAD. However, it is known to be linked to many factors, most notably smoking, diabetes, hypertension (high blood pressure), hyperlipidemia (high cholesterol), elevated levels in your blood of an amino acid called homocysteine or of a protein called C-reactive protein, and certain hereditary factors.

Additional risk factors include obesity, physical inactivity, an unhealthy diet, heavy drinking, a stressful lifestyle and a family history of heart disease. The risk also rises with age, and men have a slightly higher risk than women of acquiring CAD in their 40s or 50s.

How is coronary artery disease diagnosed?

Image of EKG A thorough physical exam and a detailed medical and family history are important first steps in diagnosing CAD. Your doctor will probably ask you about your symptoms' character and pattern of occurrence, as well as about any other health problems you may have.

Often, diagnostic tests will also be necessary, although there is no single test that can definitively diagnose CAD. Your doctor may recommend an electrocardiogram (also referred to as an ECG or EKG), which measures and records your heart's electrical activity; a chest X-ray; blood tests; an echocardiogram (an ultrasound image of your heart); a stress test; or an angiogram (also referred to as cardiac catheterization), which uses opaque dye to image your cardiovascular system. The results of the tests will help your doctor assess the extent of your CAD, including how many blood vessels are involved.

How can coronary artery disease be treated?

There are several ways that the progression of CAD can be slowed or halted, to minimize its symptoms and delay the development of its most serious consequences.

Your doctor may recommend lifestyle changes (such as losing weight, not smoking and staying active) and/or medications (including drugs that can lower your blood pressure or cholesterol level or help your heart beat more strongly, as well as anticoagulants, also known as blood thinners, especially aspirin, which may reduce the likelihood that blood clots will form). In some cases, less invasive interventions—including a procedure known as balloon angioplasty or the placement in the blocked vessel of a little mesh tube known as a stent—may be able to reopen the blockage in your coronary arteries.

But if those measures are unable to sufficiently control your symptoms, or a large number of your coronary arteries are blocked, your doctor will likely recommend an operation known as a coronary artery bypass graft—the surgical bypass of one or more of your blocked arteries. This procedure is typically very effective at restoring good circulation within your coronary arteries, as well as at relieving the symptoms of CAD and, in most cases, preventing a future heart attack.

The best approach depends on a number of factors, including the extent and severity of the blockage in your coronary arteries, your age, other diseases you may have, and your feelings about the different options. In all cases, however, early diagnosis and treatment are important, in order to slow the condition's progress.


Page reviewed on: Jun 26, 2015

Page reviewed by: Jock McCullough, MD

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