Peripheral Artery Disease and Intermittent Claudication

Description

Alternative Names

Symptoms

Intermittent claudication is the most prominent symptom of peripheral artery disease (PAD). However, PAD is just as likely to be present without symptoms or to have problems in the legs that do not resemble intermittent claudication. Because of such silent symptoms, many cases of PAD go undiagnosed.

Intermittent Claudication

Intermittent claudication is an important symptom of peripheral artery disease (PAD) and occurs in between a third and half of these patients. Claudication is taken from the Latin word "to limp" and it is the pain that occurs in PAD patients when they exercise, particularly during walking.

In intermittent claudication, blood flow in the leg is insufficient to meet the needs of the person while exercising. The most frequently affected artery in intermittent claudication is the popliteal artery. This artery leads off from the femoral artery (the major artery in the thigh). It continues below the knee where it branches off and carries blood to the muscles in the calf and foot.

In general, the following occurs during physical activity:

• In PAD, the artery becomes blocked and the free flow of blood is limited. During exercise, then, oxygen supply does not meet the muscles' demands.
• In response to this higher demand, the body reduces chemicals that open blood vessels (e.g., nitric oxide) and increases chemicals that narrow blood vessels (thromboxane, serotonin, angiotensin II, endothelin, norepinephrine).
• There is also some evidence that blood cells may become abnormal in PAD and prone to forming clots.

The result of these actions is leg pain during exercise, which is relieved only by rest. Leg pain occurs in one leg in 40% and in both legs in 60% of patients.

Symptoms of Advanced Peripheral Artery Disease (Ischemic Rest Pain)

In advanced cases, PAD obstructs the arteries in the leg to the degree that even rest offers no relief and pain can continue even when lying down, a condition called ischemic rest pain. (Ischemia is the medical term for insufficient blood flow to tissues.) In this severe situation, the arteries can become so obstructed that ulcers and gangrene can develop, leading in severe cases to amputation. Symptoms in such cases can include the following:

• Withered calf muscles.
• Hair loss over the toes and feet.
• Thick toenails.
• Shiny, tight skin.
• Painful ulcers in the toe that typically are black and do not bleed.
• In some cases, blood clots can form in the arteries in the legs, producing symptoms abruptly.