Vascular: Atherosclerosis (Arteriosclerosis)

Atherosclerosis (Arteriosclerosis)

Basics

  • Plaque Formation in Arterial Walls
  • Can Restrict Blood Flow Causing Ischemia
  • Most Common Sites: Branch Points

Stages of Atherogenesis

  • Stage 1 (Initiation): Fatty Streak
    • 1. Endothelial Dysfunction
    • 2. Fatty Streak (Flat-Slightly Raised Yellow Discoloration) Formation within the Intima
    • 3. Migration of Leukocytes & Smooth Muscle into the Vessel Wall
    • 4. Foam Cell (Macrophages that Have Absorbed Lipids) Formation
      • Primary Lipid: LDL
  • Stage 2 (Adaptation): Plaque Progression
    • Smooth Muscle Proliferation
    • Extracellular Matrix Degradation with Wall Injury
    • From Foam Cell Release of Growth Factors
  • Stage 3 (Complication): Plaque/Intimal Disruption
    • From Smooth Muscle Proliferation
    • Exposed Collagen Leads to Thrombus

Atherosclerosis 1

Risk Factors

  • Smoking
    • Endothelial Dysfunction – Decreased Nitric Oxide & Increased Reactive-Oxygen Species
    • Prothrombotic Environment – Promotes Platelet Aggregation & Increased Levels of vWF, Thrombin & Fibrin
    • Promotes Inflammation – Increased Leukocytes, CRP, IL-6 & TNF-α
  • Diabetes
  • Hyperlipidemia
  • Hypertension
  • Familial Atherosclerosis

Complications

  • Coronary Artery Disease (CAD)
  • Cerebral Vascular Disease/Carotid Stenosis
  • Peripheral Artery Disease (PAD)
  • Aneurysms
  • Chronic Kidney Disease

Carotid Plaque 2

References

  1. Npatchett. Wikimedia Commons. (License: CC BY-SA-4.0)
  2. Uthman E. Wikimedia Commons. (License: CC BY-2.0)