peripheral vascular disease pathophy Flashcards
peripheral effects of atherosclerosis
intermittent claudication
critical leg ischemia
where can you see PAD
1) aortoiliac
2) superficial fem
3) tibial
risk factors of PAD
1) diabetes (4x)
2) smoking
3) lipid
4) HTN
PAD HAS 6X INCR RISK OF CV DEATH
symptoms of PAD
intermittent claudication
NO SX AT REST, ONLY WITH EXERCISE
1) cramp
2) calf fatigue
why do you only have sx with exercise in intermittent claudication
because decr blood flow with exercise (insufficient supply and increased demand)
symptoms of PAD
ischemic rest pain/ischemic ulcers
SX AT REST AND EXERCISE
1) pain in distal foot/heel worse with leg elev, improved by depedency and dangle foot
2) distal ulcers on toes/heel
why do you have sx with exercise and rest in ischemic ulcers of PAD
decr blood flow with exercise and rest
signs of PAD
1) decr/absent pulses
2) bruit (abd/femo)
3) muscle atrophy
4) critical leg ischemia
what is critical leg ischemia
pallor of foot when raised
dependent rubor
what are important measures of arterial stenosis
1) radius of stenosis (Q = r^4)
2) length of stneosis
___ incr at higher flow velocities
hemodynamic severity
hemodynamic severity incr at ___
higher flow velocities
more turbulent flow
develop high resistant collaterals, high oxid stress
Factors that affect arterial hemodynamics
1) perfusion pressure
2) blood viscosity
3) arterial stenosis
4) flow velocity
a
a
what is the ankle-brachial index (ABI)
ABI = ankle SBP/arm SBP
if < 0.90 = PAD (occlusion/stenosis)
if 0.90 - 1.00 = atherosclerosis
normal = 1.10
why treat claudication?
1) prevent MI, stroke, vascular death
2) incr limb sx, exercise performance, and QOL
3) heal ulcers, decr limb loss
how to treat claudication?
1) surgery/angioplasty
2) exercise training incr muscle metab
3) drugs (cilostazol)
what is arterial aneurysm
expansion of ALL 3 ARTERIAL LAYERS
normal sizes of aorta in adult
3 cm at root
2.5 cm mid-descending thoracic
2 cm at infra renal
what is cut-off size for AAA
diameter > 3cm
or
50% incr in size relative to proximal normal
mechanism behind anerusym formation
1) weak aortic wall (decr elastin/collagen)
2) inflammation (B/T lymphocytes, mac, cytokine, autoantigen
3) proteolytic enzyme of collagen(incr MMP2/9)
4) stress (HTN, turbulent blood flow, mural thrombus)