Peripheral Vascular Disease

Question 1

PVD prevalence

Answer 1

• 10-12%

- 20% in pts >70 or younger w/risk factors

Question 2

PVD major risk factors

Answer 2

• diabetes
• smoking
• lipids
• hypertension

Question 3

hemodynamic changes in claudication

Answer 3

-normally laminar flow –> stenosis = drop in pressure

Question 4

a) length of the stenosis, b) radius of the stenosis and c) blood viscosity (in terms of how each contributes to a drop in pressure and flow across a stenosis)

Answer 4

a.

b. most important; smaller radius of vessel –> increase drop in pressure
c. increased blood viscosity –> increased turbulence?

Question 5

atherosclerotic disease process impact on endothelial cells modulated by NO

Answer 5

xx

Question 6

Describe the major risk factors for aortic aneurysm

Answer 6

• male gender
• age
• smoking
• family history

Question 7

relationship between the size of an aortic aneurysm and the subsequent risk of rupture

Answer 7

• increased rupture rate with increased size

- ~exponential increase in risk

Question 8

What is the 5-year risk of rupture of a 5.5 cm abdominal aortic aneurysm?

Answer 8

25%

Question 9

List the key risk factors that initiate aortic dissection

Answer 9

• HTN
• inherited disorders of connective tissue
• bicuspid aortic valve
• coarctation
• pregnancy
• aortitis
• iatrogenic (surgery, arterial catheterization)
• trauma

Question 10

Virchow’s triad and contribution to thrombosis

Answer 10

• injury –> exposes tissue factor/collagen –> induces clot formation
• abnormal flow/stasis –> increased opportunity for clot formation
• coagulation factors –> hyperactivity leads to more clot formation

Question 11

major sites of action in the clotting cascade of warfarin and heparins

Answer 11

• Warafarin = inhibits, II, VII, IX, X

- Heparin =

Question 12

Common distributions of PVD

Answer 12

• aortoiliac –> usually discrete
• superficial femoral –> often disseminated
• tibial

Question 13

Sx of PVD

Answer 13

• intermittent claudication: blood flow @ rest is normal, but flow is limited w/exercise
• ischemic rest pain/ischemic ulcers: blood flow limited @ rest and exercise –> worse w/elevation, better w/dependency

Question 14

Signs of PVD

Answer 14

• decreased, absent pulses
• bruits (abdominal, femoral)
• muscle atrophy
• w/severe PVD: dependent rubor, pallor w/elevation

Question 15

Goals of claudication therapy

Answer 15

• prevent CV events (MI, stroke, vascular death)
• improve limb symptoms, exercise tolerance
• heal ulcers and prevent limb loss

Question 16

Tx for claudification

Answer 16

• surgery or angioplasty
• exercise –> improves muscle metabolism
• drugs (cilostazol)

Question 17

True aneurysm definition vs. pseudoan

Answer 17

• true=pathological expansion of all three arterial layers

- pseudo=usually injury mediated; two layer expansion

Question 18

Common mechanisms of aneurysm

Answer 18

• weakened aortic wall (decreased elastin, collagen)
• inflammation
• proteolytic enzymes
• biomechanical stresses (e.g. hypertension)

Question 19

Aortic dissection & main mechanisms

Answer 19

• layers of vessel become “unraveled”
• vessel looses integrity
• primary intimal rent/tear –> blood flow helps induce dissection between intima and media
• rupture of vasa vosorum

Question 20

Tx of aortic dissection

Answer 20

• control change in pressure/change in time
• control BP
• control pain
• surgery

Question 21

Mechanisms of thrombophilia

Answer 21

• Thrombophilia caused by any alteration in coagulation balance that:
• increases thrombin production
• enhances platelet activation/aggregation
• mediates endothelial activation/damage
• mediates fibrinolytic inhibition