Peripheral artery disease

Question 1

Where do emboli preferentially lodge that leads to acute limb ischemia?

Answer 1

Artery bifurcations or in areas where vessels abruptly narrow

Question 2

What are the physical findings that are consistent with arterial insufficiency?

Answer 2

1) Absent or diminished pulses
2) Atrophy of calf muscles
3) Thickened toe nails
4) Loss of hair below knees
5) Thin, shiny skin
6) Non-healing wounds
7) Dependent rubot

Question 3

What are the risk factors of atherosclerotic peripheral artery disease?

Answer 3

Identical to coronary artery disease (40% of pts with PAD have clinicall significant CAD)

1) HTN
2) Hyperlipidemia
3) Smoking
4) DM
5) Family history

Question 4

How is ankle-brachial index measured and what does it indicate?

Answer 4

Ankle brachial index is measured by taking systolic blood pressure at teh arms and calves/ankles. Normally, ankle pressures hould be higher due to gravity than upper extremities (normal is 1-1.4). Moreover in a normal pt, BP should be the same after exercise. However, in a pt with peripheral artery disease, there will be a significant drop in BP in that extremity. An index of less than 0.8 means that there is moderate arterial disease.

Question 5

What is intermittent claudication and how is it qualified?

Answer 5

Reproducible and predictable ischemic muscle pain within the same muscle groups that occurs during specific amount of physical activity and is relieved after a short rest (2-5 minutes) even just standing in place.

Characterized by street blocks (e.g. 2 block claudication)

Question 6

In peripheral arteiral disease, how does the anatomical location of arterial lesion correlate with the pain?

Answer 6

Location of pain correlates with the affected artery. Usually, the pain affects distal muscles to the area of stenosis.

Question 7

What is the main difference between pain in the leg due to spinal stenosis vs pain due to intermittent claudication?

Answer 7

In intermittent claudication, pt can just stop and stand in position, and pain goes away.

In spinal stenosis, pt usually has to sit down (flex the spine) to relieve the pain

Question 8

Disease in which artery leads to claudication in the calf muscle?

Answer 8

Distal superficial femoral artery (most common area of lesion)

Question 9

What are the presentations for rest pain and what does this indicate?

Answer 9

Rest pain indicates critical narrowing or thrombus of a vessel which may lead to limb-threatening ischemia.

It usually presents as patient waking at night and due to pain. This is because at night, when they go to bed they are lying flat,making them lose pressure offered by gravity, which leads to decreased perfusion. This pain is relieved by standing up or dangling their feet down.

Question 10

Disease in which vessel leads to claudication in thigh and buttock as well as male erectile dysfunction?

Answer 10

Aortoiliac area

Question 11

Etiology of peripheral artery disease (3)

Answer 11

1) Atherosclerosis (most common)
2) Thromboembolism
3) Vasculitis

Question 12

What are the tx of intermittent claudication?

Answer 12

1) Lifestyle changes (e.g. smoking, managing lipids, etc.)
2) Progressive exercise program
3) Medications (e.g. ASA, statins)

Question 13

What causes the pain seen in peripheral artery disease during exertion?

Answer 13

When there is stenosis in a vessel, there is a pressure drop distal to the lesion so that the distal muscle groups will experience that decrease in pressure. During rest, although there is this pressure drop, there is still enough pressure to maintain perfusion so that the patients remain asymptomatic. However during exertion, there is peripheral dilitation of the vessels and the pressure drop distal to the stenosis becomes significant, which decreases perfusion, and causes symptoms.

Question 14

What is the most common cause of acute limb ishcemia

Answer 14

Emboli (in healthy pts with no collateral circulation, thrombus can cause infarction of extremity)

Question 15

Ankle brachial index less than 0.5 is indicative of what?

Answer 15

Rest pain (critical narrowing or thrombus) that may lead to limb-threatening ischemia.

Question 16

What is the most common clinical manifestation of peripheral arterial disease, and what are 2 sx that indicates a need for prompt intervention?

Answer 16

Claudication (pain w/ exertion is the most common clinical manifestation of peripheral arterial disease.

The two sx that prompt intervention is rest pain and non-healing wounds.

Question 17

What are the 5 P’s of acute limb ischemia?

Answer 17

1) Pain (very abrupt and severe)
2) Pulseless
3) Paresthesias: structures most sensitive to ischemia are nerves so these are affected first
4) Paralysis
5) Poikylothermia (cold)

Question 18

What is dependent rubor and what is it suggestive of?

Answer 18

When pt hands feet over side of bed, leg becomes hyperemic. Normally, when the feet are hung, due to increase in hydrostatic pressure of dermal arterioles and capillaries, they should constrict. However in case of peripheral artery disease, they are ischemic and damaged so they can’t constrict the way they should to maintain the pressure, leading to hyperemia. If pt lifts the leg up, the leg becomes white. This is suggestive of severe peripheral arterial disease.

Question 19

What causes atrophy of calf muscles in arterial insufficiency?

Answer 19

Due to insufficient blood supply to the calves, the muscle gets denervated leading to muscle wasting and loss of strength. However, note that in most pts, both legs are usually affected (not just one with arterial insufficiency) due to inactivity.