January 13, 2016 - Arterial Disease

Question 1

Atherothrombosis

Answer 1

Characterized by a sudden (unpredictable) atherosclerotic plaque disruption leading to platelet activation and thrombus formation. This is the major cause of acute coronary syndromes (ACS) and cardiovascular death.

Question 2

Peripheral Arterial Disease

Answer 2

Is a narrowing of the arteries other than those that supply the heart or the brain.

Most commonly affects the legs, but other arteries may be involved. The class symptom is leg pain when walking that resolves with rest, known as intermittent claudication.

Underlying mechanism is atherosclerosis.

(Pictured is an arterial insufficiency ulcer)

Question 3

Intermittent Claudication

Answer 3

A symptom that describes muscle pain (ache, cramp, numbness, or fatigue), classically in the calves, which occurs during exercise such as walking, and is relieved by a short period of rest.

It is classically associated with early-stage peripheral artery disease and can progress to critical limb ischemia unless treated or risk factors are modified.

Question 4

Critical Limb Ischemia (CLI)

Answer 4

Also referred to as “limb threat” is an advanced stage of peripheral arter disease (PAD). It includes ischemic rest pain, arterial insufficiency ulcers, and gangrene.

Critical limb ischemia has a poor prognosis with 1-year amputation rates of 12%, and 5-year mortality of 50% and 10-year mortality of 70%.

Question 5

Risk Factors for Atherothrombosis

Answer 5

Smoking

Diabetes

Hyperlipidemia

Hypertension

Age

♦ Notice that these are the same risk factors for CVD.

Question 6

Acute Limb Ischemia

Answer 6

Occurs when there is a sudden lack of blood flow to a limb.

This is caused by an embolism or thrombosis, often caused by peripheral vascular disease. Highly treatable with proper surgical care, but if treatment is delayed beyond 6-12 hours it can result in permanent disability, amputation and/or death.

Think of the 6P’s; pulseless, pain, pallor, polar (cold), paralysis, paresthesias.

Question 7

Physical Exam of Peripheral Arterial Disease

Answer 7

Have the patient take their shoes off and expose their legs.

Pay attention to… diminished pulses, hair loss, smooth, shiny skin and dystrophic nail changes.

Question 8

Buerger’s Test

Answer 8

Used in an assessment of arterial sufficiency.

The vascular angle (or Buerger’s angle) is the angle that the leg has to be raised before it comes pain.

Positive if pallor develops after limb elevation with subsequent hyperemia after lowering the limb.

A healthy leg should be able to be raised 90 degrees without issue, but with peripheral arterial disease pallor can occur with angles as low as 15 degrees.

Question 9

Ankle-Brachial Index (ABI)

Answer 9

Is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm.

Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries due to peripheral artery disease (PAD).

The ankle-brachial index is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm (higher pressure arm).

An index of >0.9 is normal and an index of <0.9 is abnormal.

0.5-0.9 = claudication

<0.5 = critical ischemia

Question 10

Treatment of Peripheral Arterial Disease

Answer 10

Supervised exercise

Smoking cessation

ASA and statins

Percutaneous coronary intervention (angioplasty / stenting)

Bypass surgery

Question 11

Treatment of Acute Limb Ischemia

Answer 11

Thrombolytics

Embolectomy

Bypass

Question 12

Abdominal Aortic Aneurysm

Answer 12

A localized enlargement of the abdominal aorta such that the diameter is greater than 3cm or more than 50% larger than normal.

Usually cause no symptoms unless when ruptured.

Screening is important in individuals over 65 via ultrasound.