17- Peripheral Arterial Disease Flashcards
define PAD
stenosis of the aorta or arteries in the limbs
leading cause of PAD in patients >40 yo
atherosclerosis
what might be the cause of PAD in a young female pt.?
fibromuscular dysplasia
does everyone with PAD know it?
nope
10-30% are symptomatic
modifiable risk factors for atherosclerosis
- DM
- HTN
- Tobacco
- Obesity
- HLD
- CKD
how is diabetes a risk factor for atherosclerosis
endothelial cell dysfunction and inflamamtion
how is HTN a risk factor for atheroscleroiss?
increased shear stress = decreased NO, increased inflammation and endothelial remodeling
how is tobacco exposure an atherosclerosis risk factor?
vasoconstriction and pro-inflammatory substances
why is obesity a risk factor for atherosclerosis?
pro-inflammatory state
the greatest risk factor for PAD
cigarette smoking
non-modifiable risk factors for atherosclerosis
male
age
race (black)
family history
leukocytes, C reactive prtn and monocytes correlate with…
serum bilirubin correlates with..
PAD is correlated with leukocytes, c-reactive prtn and monocytes (inflammatory disease)
serum bilirubin is associated with reduced PAD prevalence
oxygen demand of skeletal muscle during effort exceeds the blood’s oxygen supply =
intermittent claudication
*cardinal symptom PAD
flow through an artery is ______ related to perfusion pressure and _________ related to vascular resistance
Flow = pressure/resistance
direct
inversely
which type of fibers are lost with partial axonal denervation in legs affected by PAD?
type II glycolytic fast-twitch fibers are lost
–> decreased muscle strenght and acapacity
the hallmark of all diabetic complications is…
endothelial dysfunction
because chronic metabolic changes lead to vasoconstriction, chronic inflammation and tendency towards thrombosis
_____ vasodilatory and ______ vasoconstrictive cytokines
decreased dilatory and increased constrictive
chronic metaboic change of DM leading to endothelial dysfunction
____ coagulation factor production and _______ platelet aggregation
both increased
tendency toward thrombosis with endothelial dysfunction
how is PAD caused by chronic kidney disease CKD different than that caused by other etiologies?
calcification is predominant
preferentially affects the MEDIA and not the intima
related to abnormal Ca-Ph metabolism, and metabolic bone disease
—> stenosis without evidence of plaque on angiography
primary stie of involvement in symptomatic patients
femoral and popliteal arteries (80-90%)
edinburgh claudication questioinnaire
pain in either calf with walking and whether the pain occurs at trest, while walking at an ordinary or hurried pace or on walking uphill
history should note walking distance, speed and incline that precipitate claudication
Does the pain ever begin when standing or sitting still?
NO = IC
do you get pain if you walk uphill or hurry?
YES = IC
do you get pain if you walk at ordinary level pace?
YES = severe IC
pain goes away when stand still?
YES = IC
where does claudication typically occur?
calf muscle
pain or paresthesias in foot or toes that worsens with leg elevation and improves with dependency
critical limb ischemia
gold standard for diagnosis of PAD
contrast angiography
segmental pressure measurements indicate stenosis if…
BP gradient > 20 mmHg between cuffs in LE or 10 in UE
Normal ABI
1-1.4
abnormal when ankle is lower pressure (ABI
the lower the ABI, the …
less distance and lower speed in walking (more severe disease)
ABI > 1.4 …
calcified, non-compressible vasculature
decrease __- or more in ABI after exercise in pt with claudication is diagnostic
25%
pulse volume recording =
plethysmography
which is a better treatment: supervised exercise program or pharmacologic therapy?
both are equally efficacious
should elastic hose be used in patients with intermittent claudication?
NO should be avoided
what type of medication should all symptomatic PAD pts be taking?
antiplatelet medications
EX: cilostazol or pentoxifylline
when is endovascualr therapy not indicated?
if there is no pressure gradient across the stenosis
six Ps of acute limb ischemia
paresthesia pain pallor pulselessness poikilothermia paralysis
_____ of patients with claudication progress to critical limb ischemia. _____ of patients with critical limb ischemia go on to require amputation
10%
20-30%
atherosclerosis is a ________ disease with ____________ preference
systemic
regional
