Lecture 15: PAD Flashcards
what is the atherosclerosis?
–The formation of lipid, cholesterol, and/or calcium-laden plaques within the tunica intima of the arterial wall, which can restrict blood flow. Rupture can cause intraluminal thrombosis that results in myocardial infarction, unstable angina, and/or ischemic stroke.
in what blood vessel layer the lipid material accumulates in atherosclerosis?
1) Tunica intimia
2) tunica media
3) adventitia
Tunica intima, subintima
what are the common sites (in order of frequency) of atherosclerosis?
- -Abdominal aorta
- -Coronary arteries
- -Popliteal arteries
- -Carotid arteries
- -Atherosclerotic diseases
what is PAD?
A chronic condition characterized by the luminal narrowing of noncoronary peripheral arteries due to atherosclerotic plaques. Typically used to describe lower extremity PAD, but arteries of the bowel, kidneys, or brain can also be involved. Limb PAD can be asymptomatic or cause intermittent claudication, rest pain, or ischemic ulcers.
Does atherosclerosis cause acute or chronic symptoms?
canc ause both
what are the 3 causes of PAD?
- -occlusive disorders (acute and chronic)
- -aneurysmal disorders
- -vasculitic disorders
what is the epidemiology of PAD?
1) Prevalence: 8.5 million in the US
- -Prevalence increases with age, starting from the age of 40
- -US incidence rates are highest among African Americans, followed by Hispanics, who are at a slightly higher risk than non-Hispanic whites.
2) Peak incidence: 60–80 years of age
3) Sex: ♂ = ♀
at what age PAD is at its peak?
- -60–80 years of age
- -Patients over the age of 40 may develop PAD if risk factors are present; over the age of 80 the probability of developing PAD is high even in the absence of risk factors.
what are the PAD risk factors?
- -Older age
- -HTN
- -Smoking
- -Diabetes
- -Hypercholesterolemia
- -Ethnicity
Prevalence rates of PAD are higher in African Americans than non-Hispanic whites. T/F
True
what is the clinical presentation of PAD?
- -Claudication and atypical lower extremity pain
- -Rest pain
- -Ulceration
- -Gangrene
is intermittent claudication sensitive to PAD?
- -Intermittent claudication is a specific but not sensitive finding for PAD. Up to 40–50% of patients with PAD have atypical leg pain.
- -Atypical lower extremity pain may be more common than claudication due to comorbidities, physical inactivity, and alterations in pain perception.
what is intermittent claudication?
- -Pain, cramps, or paresthesia distal to arterial occlusion
1) Femoropopliteal disease (most common) → calf claudication
2) Aortoiliac disease (Leriche syndrome) - -Level of the aortic bifurcation or bilateral occlusion of the iliac arteries
- -Triad of bilateral buttock, hip, or thigh claudication, erectile dysfunction, and absent/diminished femoral pulses
3) Tibiofibular disease→ foot claudication - -Worsens upon exertion , completely relieved by rest or lowering affected limbs
- -Reproducible when the patient is asked to walk the same distance as when he/she was symptomatic
what is the rest pain?
Rest pain is a continuous burning pain of the lower leg or feet. It begins, or is aggravated, after reclining or elevating the limb and is relieved by sitting or standing.
rest pain indicates…
- -Rest pain occurs as the disease progresses and indicates severe ischemia.
- -Typically in distal metatarsals
- -Worse at night
- -Improved when hanging feet over bed or standing
what is the ulcer?
An ulcer is a breach of the continuity of the skin, epithelium or mucous membrane caused by sloughing out of inflamed necrotic tissue.
what are the features of arterial ulcers?
- -Punched-out appearance
- -Intensely painful
- -Grey or yellow fibrotic base and undermining skin margins
- -Pulses are not palpable
- -Most common on distal ends of limbs
- -Can have associated skin changes- shiny skin, absence of hair
what are the common locations of arterial ulcers?
Usually involves the foot, particularly pressure points (e.g., lateral malleolus, tips of the toes)
what is the gangrene?
Gangrene is a type of tissue death caused by a lack of blood supply
dry vs wet gangrene?
Tissue necrosis (tissue death) that usually occurs as a result of inadequate blood perfusion. Inadequate arterial perfusion (e.g., in peripheral artery disease) results in sharply demarcated gangrene with dry/mummified necrotic tissue (dry gangrene). Gangrene due to bacterial infection or venous obstruction results in poorly demarcated, exudative gangrene that spreads rapidly and is associated with systemic infection (wet gangrene)
dry gangrene is a type of liquefactive necrosis.True/False
False
–Dry gangrene is a from of coagulative necrosis that develops in ischaemic tissue where blood supply is inadequate to keep tissue viable.
–The affected part is dry, shrunken and dark reddish-black. This usually brings about complete separation, with eventual falling off of the gangrene if not removed surgically- a process known as autoamputation
wet gangrene is a type of liquefactive necrosis. T/F
True