Coronary Artery Disease

Coronary artery disease is a condition that results from arteriosclerosis (hardening of the arteries). The most frequent type of arteriosclerosis involves the accumulation of fat deposits inside the coronary arteries (atherosclerosis). This process usually occurs over many years and may not be detected until symptoms occur. Like the process of rust build-up inside pipes, these blockages decrease the flow of blood through the coronary arteries and diminish the amount of oxygen and nutrients the heart muscle receives. Therefore, the heart muscle is starved of the oxygen and food necessary to function properly.

When the blockages become severe enough, symptoms of "angina" usually occur. Angina is the medical term used to describe the chest-pain or discomfort caused by the lack of oxygen and nutrients flowing to the heart muscle. Patients may complain of chest tightness, heaviness, burning, fullness or sharp pain across the center of the chest. This discomfort may also travel to the arms, neck, jaw and back areas. It usually lasts a few minutes, comes on, varied activity or stress and may be relieved by resting and/or nitroglycerin pills. Prolonged episodes of angina may lead to a heart attack (myocardial infarction) which means death of a portion of the heart muscle.

It is also possible to have severe blockages of the coronary arteries and have very few, if any, symptoms of angina. Shortness of breath, fatigue or indigestion complaints may be the only signals of a diminished blood supply to the heart muscle.

The exact cause of coronary artery disease is unknown. However, certain physical conditions and living habits called "risk factors" can increase the chances of developing this disease process.

Risk factors are grouped into 2 types: 1) MODIFIABLE (habits that are possible to control or change) and 2) NON-MODIFIABLE (characteristics that cannot be changed or altered).

Modifiable Risk Factors

1. Cigarette smoking
2. High blood pressure
3. Diabetes
4. High fat diet/High blood cholesterol levels
5. Overweight condition
6. Lack of exercise
7. Stress or tension

Non-Modifiable Risk Factors

8. Family history of heart disease
9. Gender
10. Aging process

Coronary artery disease can develop in persons who have few or no risk factors. Those persons with several risk factors greatly multiply their chances of developing atherosclerosis and subsequent coronary disease. There is no medical or surgical cure for coronary artery disease. Risk factor modification may help control or retard future coronary artery disease.

Coronary Artery Bypass Operation ( Bypass Surgery )

A coronary artery bypass operation is the operative treatment for diseased coronary arteries. One end of a segment of vein, usually removed from the leg, is sewn into the coronary artery below where the blockage occurs and the other end is attached into the aorta. This vein graft by- passes the blockage in the coronary artery and allows improved blood flow to areas of the heart muscle not receiving an adequate oxygen supply. Multiple segments of vein are used for multiple blockages. The artery blockages are not usually removed or cleaned out, simply bypassed much like a road detour for a traffic jam. Occasionally, a portion of the inside of the artery is surgically removed; this is known as an endarterectomy. The remaining veins in the leg learn to increase their work capacity and make up for the missing section of vein. This operation on the leg does not affect walking or normal use of the leg.

In some cases the right and left internal mammary arteries, located on either side of the breastbone, can be used to construct bypasses.

The coronary artery bypass procedure is not a cure for coronary artery disease. However, the improved blood supply to the heart muscle should help relieve angina, enable you to be more active and improve the heart's ability to function as a pump.

Acknowledgements
Content: Jaelene K. Williams, RN, MS
Medical Illustrations: Kathleen Wagner
Illustrations: Catherine Gendron