Critical Care Exam 2 latest complete study guide 2024
Coronary Atherosclerosis (CA) An abnormal accumulation of lipid, or fatty
... [Show More] substances, and fibrous tissue in the lining of arterial blood vessel walls.
CA Pathophysiology: -Inflammatory response due to injury to the vascular endothelium and progresses over many years
-Injury may be initiated by smoking or tobacco use, hypertension, hyperlipidemia, and other factors
-Endothelium changes and stops producing normal antithrombotic and vasodilating agents, presence of inflammation attracts inflammatory cells, such as macrophages, macrophages ingest lipids, becoming "foam cells" that transport the lipids into the arterial wall, some of the lipid is deposited on the arterial wall, forming fatty streaks, activated macrophages also release biochemical substances that can further damage the endothelium by contributing to the oxidation of low-density lipoprotein (LDL)
-Smooth muscle cells proliferate and form a fibrous cap over a core filled with lipid and inflammatory infiltrate, these deposits (atheromas, or plaques) protrude into the lumen of the vessel, narrowing it and obstructing blood flow
-If the fibrous cap over the plaque is thick and the lipid pool remains relatively stable, it can resist the stress of blood flow and vessel movement
-If the cap is thin and inflammation is ongoing, the lesion becomes what is called vulnerable plaque
-Ruptured plaque attracts platelets and causes thrombus formation, a thrombus may then obstruct blood flow, leading to acute coronary syndrome (ACS)
-Atherosclerotic lesions most often form where the vessels branch and with turbulent blood flow, suggesting a hemodynamic component is involved in their formation
-Other causes of decrease blood flow to the heart: vasospasm (sudden constriction or narrowing) of a coronary artery and profound hypotension
CA Manifestations: -Depends on location, degree of narrowing, thrombus formation, and obstruction of blood flow to myocardiaum
-Ischemia (causes angina pectoris)
-Persistently low cardiac output and heart failure
-Sudden cardiac death (decrease in blood supply from CAD may cause the heart to abruptly stop beating)
-Epigastric distress and pain that radiates to the jaw or left arm
-Shortness of breath
-Most common manifestation of myocardial ischemia is the onset of chest pain
-Women: indigestion, nausea, palpitations, and numbness, prodromal symptoms may occur (e.g., angina a few hours to days before the acute episode), or a major cardiac event may be the first indication of coronary atherosclerosis
Nonmodifiable Risk Factors: -Family history of CAD (first-degree relative with cardiovascular disease at 55 years of age or younger for men and at 65 years of age or younger for women)
-Increasing age (more than 45 years for men; more than 55 years for women)
-Gender (men develop CAD at an earlier age than women
-Race (higher incidence of heart disease in African Americans than in Caucasians)
-History of premature menopause (before age 40) and history of pregnancy-associated disorders such as preeclampsia
-Primary hypercholesterolemia (a genetic condition resulting in elevated LDL)
Modifiable Risk Factors: -Hyperlipidemia
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