Chapter 18

Question 1

Coronary Heart Disease (CHD) or Coronary Artery Disease (CAD)

Answer 1

• characterized by insufficient delivery of oxygentated blood to the myocardium due to atherosclerotic coronary arteries

Question 2

Sequelae of CHD

Answer 2

• angina pectoris
• myocardial infarction
• Dysrhythmias
• Heart Failure
• Sudden cardiac death

Question 3

Etiology of CHD

Answer 3

• known risk factors include atherosclerosis, possible microcirculation abnormalities
• atherosclerosis causes narrowing of the arterial lumen that can lead to cardiac ischemia through thrombus formation, coronary vasospasm, and endothelial cell dysfunction

Question 4

Mechanisms of Coronary Atherosclerosis

Answer 4

• Atherosclerotic plaque formation initiated by injury to coronary artery endothelium
• endothelium becomes permeable and recruits leukocytes
• LDL accumulation occurs with oxidation by endothelial cells and macrophages
• oxidized lipids are damaging to endothelial and smooth muscle cells, and stimulate recruitment of macrophages into the vessel
• these macrophages engulf the lipids, forming foam cells which release inflammatory mediators and growth factors, attracting more leukocytes and stimulating smooth muscle proliferation
• excess lipid and debris accumulate within vessel wall and combine into lipid core, creating VULNERABLE PLAQUES

Question 5

Vulnerable Plaque

Answer 5

• may rupture or become eroded, which stimulates clot formation on the plaque
• vulnerable plaques have a large lipid core, thin cap, and high shear stress

Question 6

Increased plaque vulnerability causes

Answer 6

• active inflammation within the plaque
• large lipid core with a thin cap
• endothelial denudation (erosion)
• fissured or ruptured cap
• severe stenosis

Question 7

Treating Atherosclerosis

Answer 7

• lipid lowering therapy: mainstay of treatment and prevention for atherosclerosis; also stabilize the plaques, making them less prone to rupture

Question 8

Acute Coronary Syndrome (ACS)

Answer 8

• decreased blood flow in arteries that causes the heart to stop functioning properly or die
• associated with acute changes in plaque morphology and thrombosis; abrupt and can be life threatening
• unstable angina
• myocardial infarction