Table of Contents
Definition of Atherosclerosis
Atherosclerosis is Accumulation of lipids and other materials (atherosclerotic plaque) between the two layers of an artery’s inner wall, the intima. Over time the accumulations form brittle, hard deposits called atheromas that thicken the intima and the media (the middle of the arterial wall’s three layers). The usual consequence is that the artery becomes stiff and less flexible, and its inner channel, the lumen, narrows.
The combined effect limits the ability of the artery to dilate or constrict, increasing the pressure necessary to push blood through the artery. The result is cardiovascular disease (cvd), including hypertension (high blood pressure), coronary artery disease (cad), and peripheral vascular disease (pvd).
Atherosclerosis takes decades to develop. Many researchers believe the process of atherosclerotic accumulation begins in late childhood.
Atherosclerosis will most commonly affect medium-size arteries such as the coronary arteries that supply the heart, the carotid arteries that supply the brain, and the primary arteries that supply the legs. Atherosclerosis can also develop in the large arteries, notably the aorta – in the aorta presents a significant risk for aortic aneurysm, a potentially life-threatening circumstance in which the walls of the aorta weaken and begin to separate.
The most significant risk of atherosclerosis, however, is heart attack or stroke, resulting from particles of atherosclerotic plaque that break free and become lodged in an artery. The blockage may occur at the location of the occlusion or at a distant site. Blood clots also may form at the sites of the plaque accumulations (atheromas), occluding the artery at the site or, like the plaque particles, breaking free and becoming lodged elsewhere in the body.
Symptoms and Diagnostic Path
Atherosclerosis typically does not present symptoms until it advances to a further disease state such as CAD or hypertension resulting from renal artery stenosis. A key indicator that atherosclerosis exists, however, is elevated blood lipid (cholesterol and triglycerides) levels. Cardiologists generally perceive a total blood cholesterol level of 200 as indicating that there is some degree of atherosclerotic disease present.
Lowering cholesterol blood levels reduces the risk for further atherosclerotic deposits and can also reverse to some extent atherosclerotic disease that already exists. The diagnostic path typically includes cardiac catherization or vascular catheterization, which allows the cardiologist to directly visualize the extent of atherosclerotic disease present. Electron beam computed tomography (ebct) scan, a noninvasive imaging procedure, shows promise for identifying atherosclerosis in its early stages. EBCT detects calcium in the atherosclerotic deposits.
Treatment Options and Outlook
Treatment may target the damaged arteries, the underlying disease process, or both. Treating the damaged artery generally takes precedence as the atherosclerotic occlusions restrict and may even block the flow of blood.
Risk Factors and Preventive Measures
The primary risk factor for atherosclerosis is elevated cholesterol blood levels, which allow fatty acids to accumulate in the blood. Cigarette smoking, obesity, hypertension, and diabetes further increase the risk for atherosclerosis. Cigarette smoking and hypertension alter the cells of the arterial walls in ways that reduce their flexibility, making them more susceptible to atherosclerotic accumulations. Diabetes and obesity both alter lipid metabolism.
Preventive measures include a diet with fewer than 10 percent of its calories from saturated fats (such as meats), daily physical exercise, smoking cessation, and weight loss and weight management. Health experts encourage people to develop heart-healthy lifestyle habits early in life, as so much research now confirms that the cardiovascular diseases common in people who are in their 60s and beyond get their start in the teenage years or earlier.
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