Peripheral Artery Disease Testing
Peripheral artery disease (PAD) is often caused by atherosclerosis, an accumulation of plaque in the peripheral arteries, which carry blood to the arms, legs and internal organs. Atherosclerosis causes the peripheral arteries to narrow and harden, and/or become blocked. By reducing the amount of blood that flows to the limbs and organs, atherosclerosis increases the risk of heart attack, stroke and transient ischemic attack. It can also cause limbs to become infected and, in severe cases, gangrenous.
Various instruments and tests are used to detect the presence of PAD. They include blood-pressure cuffs, Doppler and intravascular ultrasounds, angiograms, magnetic resonance imaging (MRI) scans and venograms.
The diagnostic test most often performed when investigating the possible presence of PAD is the ankle-brachial index (ABI),in conjunction with a Doppler ultrasound blood-flow detector. During an ankle-brachial index test, blood pressure in the leg is compared with blood pressure in the arm. The ankle-brachial index evaluates blood flow in a patient complaining of leg or arm pain, numbness, tingling and fatigue, all of which are symptoms of narrowing, hardening and blockage of the arteries. Doppler technology uses sound waves to detect blood flow, and identify any differences in blood pressure, in the arms and legs. During the arterial Doppler ultrasound, a transducer is used to detect blood flow before and after a blood-pressure cuff is inflated. Patients may experience mild cramping because the cuffs cut off circulation. ABI using Doppler ultrasound usually takes about 45 minutes to perform, and patients can return to their regular activities immediately afterwards.
After a diagnosis of PAD, other tests, including CT scans and X-rays, may be necessary to evaluate its severity, and the best method for treating it.