Atherosclerosis overview
| https://https://www.youtube.com/watch?v=MjC1-odNY5k%7C350}} |
|
Atherosclerosis Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
ACC/AHA Guideline Recommendations |
|
Case Studies |
|
Atherosclerosis overview On the Web |
|
American Roentgen Ray Society Images of Atherosclerosis overview |
|
Risk calculators and risk factors for Atherosclerosis overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Atherosclerosis is a disease affecting arterial blood vessels. It is a chronic inflammatory response in the walls of arteries, in large part due to the deposition of lipoproteins (plasma proteins that carry cholesterol and triglycerides). It is commonly referred to as a "hardening" or "furring" of the arteries. It is caused by the formation of multiple plaques within the arteries.
Pathophysiology
Atherogenesis is the developmental process of atheromatous plaques. It is characterized by a remodeling of arteries involving the concomitant accumulation of fatty substances called plaques. One recent theory suggests that for unknown reasons, leukocytes such as monocytes or basophils begin to attack the endothelium of the artery lumen in cardiac muscle. The ensuing inflammation leads to formation of atheromatous plaques in the arterial tunica intima, a region of the vessel wall located between the endothelium and the tunica media and tunica adventitia. The bulk of these lesions are made of excess fat, collagen, and elastin. Initially, as the plaques grow only wall thickening occurs without any narrowing, stenosis of the artery opening, called the lumen; stenosis is a late event which may never occur and is often the result of repeated plaque rupture and healing responses, not the just atherosclerosis process by itself.
Diagnosis
History and Symptoms
According to United States data for the year 2004, for about 65% of men and 47% of women, the first symptom of atherosclerotic cardiovascular disease is heart attack or sudden cardiac death (death within one hour of onset of the symptom).
Laboratory Findings
Cardiac stress testing, traditionally the most commonly performed non-invasive testing method for blood flow limitations generally only detects lumen narrowing of ~75% or greater, although some physicians advocate that nuclear stress methods can detect as little as 50%.
Treatment
Medical Therapy
If atherosclerosis leads to symptoms, some symptoms such as angina pectoris can be treated. Non-pharmaceutical means are usually the first method of treatment, such as cessation of smoking and practicing regular exercise. If these methods do not work, medicines are usually the next step in treating cardiovascular diseases, and with improvements, have increasingly become the most effective method over the long term. However, medicines are criticized for their expense, patented control and occasional undesired effects.
Future or Investigational Therapies
Since about 2002, progress in understanding and developing techniques for modulating immune system function so as to significantly suppress the action of macrophages to drive atherosclerotic plaque progression are being developed with considerable success in reducing plaque development in both mice and rabbits. Plans for human trials, hoped for by about 2008, are in progress. Generally these techniques are termed immunomodulation of atherosclerosis.