What is atherosclerosis, and how does it threaten myocardial perfusion?

What is atherosclerosis, and how does it threaten myocardial perfusion?

• A. Atherosclerosis is the dilation of arteries due to loss of elastin
• B. Atherosclerosis is the buildup of lipid-rich plaques in arterial walls, narrowing the lumen and potentially causing coronary ischemia or infarction
• C. Atherosclerosis is inflammation of venous valves
• D. Atherosclerosis is increased hematocrit causing clots

Answer: (B)

Atherosclerosis is the buildup of lipid-rich plaques inside the walls of arteries, which narrows the lumen and can destabilize to cause clots. This plaque formation starts with injury to the inner lining of the vessel, uptake of LDL cholesterol by immune cells, and layers of cholesterol, inflammatory cells, and smooth muscle that form a plaque. As the plaques grow, the artery becomes narrower, so the blood flow to the heart muscle (myocardial perfusion) is reduced, especially during exercise when the heart needs more oxygen. If a plaque ruptures, a clot can form quickly and block the artery, leading to ischemia or a heart attack. Other options describe conditions that are not atherosclerosis: dilation of arteries from loss of elastin points to aneurysm; inflammation of venous valves describes a venous problem; and increased hematocrit causing clots refers to blood viscosity issues, not plaque buildup in arteries.

Atherosclerosis is the buildup of lipid-rich plaques inside the walls of arteries, which narrows the lumen and can destabilize to cause clots. This plaque formation starts with injury to the inner lining of the vessel, uptake of LDL cholesterol by immune cells, and layers of cholesterol, inflammatory cells, and smooth muscle that form a plaque. As the plaques grow, the artery becomes narrower, so the blood flow to the heart muscle (myocardial perfusion) is reduced, especially during exercise when the heart needs more oxygen. If a plaque ruptures, a clot can form quickly and block the artery, leading to ischemia or a heart attack.

Other options describe conditions that are not atherosclerosis: dilation of arteries from loss of elastin points to aneurysm; inflammation of venous valves describes a venous problem; and increased hematocrit causing clots refers to blood viscosity issues, not plaque buildup in arteries.