Cardiovascular Pathophysiology

Question 1

Name the arteries of the heart.

Answer 1

Question 2

Mechanisms of cardiovascular disease?

Answer 2

1. Failure of the Pump
2. Obstruction to Flow
3. Regurgitant Flow
4. Shunted Flow
5. Disorders of Cardiac Conduction
6. Rupture of the Heart or Major Blood Vessel

Question 3

Normal Ventricular Wall Thickness?

Answer 3

Right: 0.3-0.5cm

Left: 1.3-1.5cm

Question 4

Normal Cardiac Weight?

Answer 4

Females: 250-300g

Males: 300-350g

Question 5

What’s the difference in pathology in these pictures?

Answer 5

Left: Hyaline arteriosclerosis from benign essential hypertension. Deposition of materials around arterioles.

Right: Hyperplastic arteriosclerosis associated with malignant hypertension. “Onion skin appearance.” Proliferation of SMCs around arterioles.

Question 6

Describe the pathology of atherosclerosis.

Answer 6

Atherosclerosis is a chronic inflammatory and healing response to arterial wall and endothelial injury.

1. Endothelial Injury/Dysfunction
   
   1. Mechanical denudation, immune complex deposition, irradiation, chemicals
   2. Hemodynamic disturbances, hypercholesterolemia, hypertension, smoking, infectious agents, homocysteine
2. Lipoprotein Accumulation
   
   1. Lipid accumulation reduced vasodilation ability of vessles
   2. Hyperlipidemia increases O2 free radicals –> NO decay
3. Monocyte Adhesion and Formation of Foam Cells
   
   1. O2 free radicals –> oxidies LDL
   2. Ingested by macrophages = foam cells
   3. Oxidized LDL –> increases release of growth factors, cytokines and chemokines that increases monocyte recruitment; cytotoxic to endothelial cells and SMC causing endothelial cell dysfunction
4. Platelet Adhesion
5. Smooth Muscle Cell Adhesion
   
   1. Atherosclerotic lesions are in a chronic inflammatory state (T-lymphocytes)
   2. Chemokines and growth factors produced promote SMC proliliferation and ECM synthesis
   3. Converts fatty streak –> mature atheroma
6. Smooth Muscle Cell Proliferation and ECM Production
7. Lipid Accumulation

Question 7

Where do plaques tend to form?

Answer 7

Ostia of exiting vessels

Branch points

Posterior wall of abdomina aorta

(Non-turbulent, laminar flow protects against atherosclerosis.)

Question 8

What are the dominant lipids in atherosclerotic plaques?

Answer 8

Cholesterol and Cholesterol esters.

Question 9

At what vascular occlusion percentage does critical stenosis occur?

Answer 9

70%

Question 10

Risks with acute change of an atherosclerotic plaque?

Answer 10

Aneurysm and Rupture

Occlusion by Thrombus