enzymes which cause enlargement of the artery over time to compensate for the extra thickness of the atheroma and prevent stenosis. This can result in aneurysm formation. This process can take place over decades without producing symptoms.
If the fibrous cap over the atheroma ruptures, atheroma tissue fragments are released into the blood stream, promoting blood clot formation, leading to a temporary covering of the rupture and some narrowing of the artery (What). This can be a repetitive event over time, and may lead to severe arterial stenosis. Seventy-fiver percent stenosis is the severity at which recurring episodes of angina and abnormal reactions to a stress test occur.
Atherosclerosis begins early in life, sometimes in late childhood, but causes no symptoms and is not recognized by any diagnostic tests in the early stages (What). It usually becomes symptomatic when it interferes with the coronary or cerebral circulation. Atherosclerosis is the major underlying cause of strokes, heart attacks, and various coronary diseases including congestive heart failure. It is the major cause of death and disability in most industrialized nations. In coronary artery disease, atherosclerosis narrows the coronary arteries, compromising the blood supply to the muscle of the heart. It triggers angina and myocardial infarctions. Coronary artery disease affects roughly 11 million people in the United States.
If a blood clot (thrombus) forms inside a cerebral artery narrowed by atherosclerosis, it cuts off the blood supply to a certain area of the brain and a stroke may occur (What). Roughly 75 percent of strokes in industrialized nations are thrombotic strokes; the remainder are hemorrhagic strokes. If atherosclerosis narrows the arteries supplying blood to the intestines, abdominal angina occurs, and sudden, complete blockage of the blood supply to the intestine can cause bowel infarction. In the extremities, atheroscle...