{"id":4422576,"date":"2025-01-12T06:25:00","date_gmt":"2025-01-12T12:25:00","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/atherosclerosis\/"},"modified":"2025-01-12T06:28:55","modified_gmt":"2025-01-12T12:28:55","slug":"atherosclerosis","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/atherosclerosis\/","title":{"rendered":"Atherosclerosis"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">OVERVIEW OF ATHEROSCLEROSIS<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition<\/strong>: A chronic inflammatory disorder of arteries characterized by plaque buildup (atheroma) in the arterial walls.<\/li>\n\n\n\n<li><strong>Clinical Impact<\/strong>:\n<ul class=\"wp-block-list\">\n<li>May lead to <strong>vascular disease<\/strong> (coronary heart disease [CHD], peripheral vascular disease, cerebrovascular disease).<\/li>\n\n\n\n<li>A major cause of <strong>disability and death<\/strong> from occlusive arterial disease.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PATHOPHYSIOLOGY OF ATHEROSCLEROSIS<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Arterial Wall Layers<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Endothelial layer<\/li>\n\n\n\n<li>Intima\/subendothelial space<\/li>\n\n\n\n<li>Internal elastic lamina<\/li>\n\n\n\n<li>Media (smooth muscle cells)<\/li>\n\n\n\n<li>Adventitia (loose connective tissue)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Sites of Lesions<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Arterial regions with <strong>turbulent flow<\/strong> (bifurcations, curvatures).<\/li>\n\n\n\n<li>Common symptomatic locations: <strong>proximal left anterior descending coronary artery<\/strong>, <strong>proximal renal arteries<\/strong>, <strong>carotid bifurcations<\/strong>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Initiating Event<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Chronic endothelial injury<\/strong> or dysfunction.<\/li>\n\n\n\n<li>Key risk factors damaging endothelium:\n<ul class=\"wp-block-list\">\n<li>Elevated <strong>low-density lipoprotein (LDL)<\/strong><\/li>\n\n\n\n<li>Decreased <strong>high-density lipoprotein (HDL)<\/strong><\/li>\n\n\n\n<li><strong>Oxidant stress<\/strong> (cigarette smoking, hypertension, diabetes)<\/li>\n\n\n\n<li>Aging<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Fatty Streak Formation<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>LDL<\/strong> (and other apo B100\u2013containing lipoproteins) move from blood into subendothelial space.<\/li>\n\n\n\n<li><strong>Retention of LDL<\/strong> by charge interactions with proteoglycans.<\/li>\n\n\n\n<li>LDL <strong>oxidation<\/strong> \u2192 promotes monocyte chemotaxis.<\/li>\n\n\n\n<li><strong>Monocytes<\/strong> enter subendothelium, become <strong>macrophages<\/strong>, and ingest oxidized LDL \u2192 <strong>foam cells<\/strong>.<\/li>\n\n\n\n<li>Clusters of foam cells = <strong>fatty streak<\/strong>, which can regress or advance.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Progression to Fibrous Plaque<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Further accumulation of <strong>foam cells<\/strong> + <strong>smooth muscle cells<\/strong> + extracellular matrix.<\/li>\n\n\n\n<li>Smooth muscle cells proliferate, produce collagen, and form a <strong>fibrous cap<\/strong> over a lipid-filled <strong>necrotic core<\/strong>.<\/li>\n\n\n\n<li>Chronic inflammation (monocytes, T cells) continues, releasing cytokines, proteases, and growth factors.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Complicated Lesions<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Plaque may <strong>rupture<\/strong> or <strong>erode<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Exposes subendothelial tissue \u2192 <strong>thrombosis<\/strong> formation.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Microvessels<\/strong> (from vasa vasorum) can rupture within plaque \u2192 small hemorrhages.<\/li>\n\n\n\n<li><strong>Calcification<\/strong>: late event with decreased arterial elasticity.<\/li>\n\n\n\n<li><strong>Cardiac CT<\/strong> can detect coronary calcification (indicates severity of atherosclerosis).<\/li>\n\n\n\n<li>Plaque <strong>rupture<\/strong> leads to acute ischemic events (e.g., myocardial infarction).<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">RISK FACTORS FOR ATHEROSCLEROSIS<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Hypercholesterolemia (\u2191 LDL)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Strong predictor of CHD.<\/li>\n\n\n\n<li>More than 70% of individuals with <strong>premature CHD<\/strong> have hyperlipidemia.<\/li>\n\n\n\n<li>Serum total cholesterol &lt;160 mg\/dL markedly reduces CHD risk.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Hypertension<\/strong>\n<ul class=\"wp-block-list\">\n<li>Elevated blood pressure injures endothelium.<\/li>\n\n\n\n<li>Hypertension control \u2192 reduces risk of stroke, heart failure, and CHD events.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cigarette Smoking<\/strong>\n<ul class=\"wp-block-list\">\n<li>Increases vascular inflammation and LDL oxidation \u2192 promotes atherosclerosis.<\/li>\n\n\n\n<li>Major modifiable risk factor.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/diabetes-mellitus\/\"  data-wpil-monitor-id=\"285\">Diabetes Mellitus<\/a><\/strong>\n<ul class=\"wp-block-list\">\n<li>Substantially increases atherosclerotic risk.<\/li>\n\n\n\n<li>Mechanisms: small dense LDL, low HDL, hyperglycemia-induced glycosylation of LDL, etc.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Others\/Associated Factors<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Low HDL<\/strong>, aging, physical inactivity, obesity, <a href=\"https:\/\/myendoconsult.com\/learn\/homa-ir-calculator\/\"  data-wpil-monitor-id=\"286\">insulin resistance<\/a>.<\/li>\n\n\n\n<li>Diet high in saturated fats.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">CLINICAL COURSE<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Lesion Evolution<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Initially silent; advanced disease \u2192 chronic stable syndromes (e.g., <strong>stable angina<\/strong>, <strong>intermittent claudication<\/strong>) or acute syndromes (e.g., <strong>myocardial infarction<\/strong>, <strong>stroke<\/strong>).<\/li>\n\n\n\n<li>Most plaques remain asymptomatic or cause progressive luminal narrowing.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Plaque Stabilization vs. Vulnerability<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Stable plaques<\/strong>: thick fibrous caps, small lipid cores.<\/li>\n\n\n\n<li><strong>Vulnerable plaques<\/strong>: thin fibrous caps, large lipid cores, high macrophage content.<\/li>\n\n\n\n<li>Ruptured plaques with superimposed thrombus \u2192 acute events and <strong>sudden cardiac death<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>OVERVIEW OF ATHEROSCLEROSIS PATHOPHYSIOLOGY OF ATHEROSCLEROSIS RISK FACTORS FOR ATHEROSCLEROSIS CLINICAL COURSE<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[688],"class_list":["post-4422576","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-lipid-metabolism","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422576","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":3,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422576\/revisions"}],"predecessor-version":[{"id":4422580,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422576\/revisions\/4422580"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422576"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422576"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}