Diagnosing Peripheral Artery Disease

In addition to gathering your medical history and performing a thorough physical exam, there are many tests and tools available to help determine if you have peripheral artery disease and its severity. During your visit, your doctor will listen to your heart, take your heart rate and check your blood pressure.

Checking your heart rate

Your doctor feels your pulse in order to check your heart's rate, rhythm, and regularity. Each pulse matches up with a heartbeat that pumps blood into the arteries. The force of the pulse also helps evaluate the amount (strength) of blood flow to different areas of your body.

You can tell how fast your heart is beating (heart rate) by feeling your pulse. Your heart rate is the amount of times your heart beats in one minute.

To measure your pulse, all you need is a watch with a second hand.

• Place your index and middle finger of your hand on the inner wrist of the other arm, just below the base of the thumb. You should feel a tapping or pulsing against your fingers.
• Count the number of taps you feel in 10 seconds.
• Multiply that number by six to find out your heart rate for one minute (pulse in 10 seconds x six = ____ beats per minute)

When feeling your pulse, you can also tell if your heart rhythm is regular or not.

Checking your heartbeat

Your doctor listens to your heartbeat with the aid of a stethoscope. The opening and closing of your valves make a "lub dub" noise known as heart sounds. The doctor can evaluate your heart and valve function and hear your heart's rate and rhythm by listening to your heart sounds.

Checking your blood pressure

Blood pressure is the force or pressure exerted in the arteries by the blood as it is pumped around the body by the heart. It is recorded as two measurements:

• Systolic blood pressure. Pressure in the arteries during the period of the heart's contraction (the higher number)
• Diastolic blood pressure. Pressure in the arteries when the heart is relaxed, between heartbeats (the lower number)

Blood pressure is measured in millimeters of mercury (mm Hg), which refers to how high the pressure in the arteries can raise a column of mercury in a sphygmomanometer, a device for measuring blood pressure.

Normal blood pressure for an adult, relaxed at rest, is less than or equal to 120 over 80. The 120 is the systolic pressure; the diastolic pressure is 80. Blood pressure may increase or decrease, depending on your age, heart condition, emotions, activity, and the medications you take. One high reading does not mean you have high blood pressure. It is necessary to measure your blood pressure at different times while resting to find out your typical value.

Checking your heart by a physical exam

Your doctor can also tell about your heart's function by examining other parts of your body, such as your eyes, arms, legs, and skin.

Checking your heart through blood tests

Your doctor may recommend a blood test to check your cholesterol and other markers that may indicate heart disease.

Rose criteria

A test used by many medical professionals to screen for peripheral artery disease is a series of 9 questions called the Rose criteria. The answers to these questions indicate whether you have peripheral artery disease and how severe it is.

Ankle/brachial index

One of the most widely used tests for a person who has symptoms suggesting intermittent claudication is the Ankle/Brachial Index (ABI).

• This test compares the blood pressure in the arm (brachial) with the blood pressure in the legs. In a person with healthy blood vessels, the pressure should be higher in the legs than in the arms.
• The blood pressure is taken in both arms in the usual way. It is then taken at both ankles. The pressure at each ankle is divided by the higher of the 2 pressures from the arms. An ABI above 0.90 is normal; 0.70-0.90 indicates mild peripheral vascular disease; 0.50-0.70 indicates moderate disease; and less than 0.50 indicates severe peripheral vascular disease.

Pulse volume recording (PVR)

This is a noninvasive test t hat measures the blood volume changes that occur in the legs. During this test, a blood pressure cuff is placed on the arm and multiple cuffs are placed on the legs. The cuffs are inflated slightly while the patient is lying down. As blood pulses through the arteries, the blood vessels expand, causing an increase or decrease in the volume of air within the cuff. A recording device displays these pulse volume changes as a waveform on a monitor. Blood pressures are measured before and after exercise on a treadmill and help define if the pain is due to PAD or other causes. The PVR test also helps locate the area of blockage sin the legs.

Vascular ultrasound

This is a noninvasive test used to examine blood circulation, During a vascular ultrasound, a transducer (small hand-held device) is placed on the skin over the artery to be examined. The transducer emits sound waves that bounce off the artery. These sound waves are recorded, and an image of the vessel is created and displayed on a monitor. This test may be used to detect a blockage in an artery.

Treadmill test

If necessary, the ABI will be followed by a treadmill exercise test.

• Blood pressures in your arms and legs will be taken before and after exercise (walking on a treadmill, usually until you have symptoms).
• A significant drop in leg blood pressures and ABIs after exercise suggests peripheral vascular disease.
• Alternative tests are available if you are unable to walk on a treadmill.
• If the leg pulses are not palpable, the use of a portable Doppler Flow Probe will quickly reveal the absence or presence of an arterial flow.

Angiography or arteriography

• During this test an x-ray dye is injected into the arteries in question; the dye highlights blockages and narrowing of arteries on an x-ray. This is an invasive study performed in a catheterization or interventional radiology laboratory. The x-ray dye must be excreted by the kidneys. If you have diabetes or already have kidney damage, the dye may precipitate further damage to your kidneys and, rarely, cause acute renal or kidney failure requiring dialysis.
• Some people describe the angiogram (x-ray obtained from angiography) as a "road map" of the arteries.
• Angiography has for many years been considered the best test available and has been used to guide further treatment and surgery.

• Certain treatments for blocked arteries can be performed at the same time, such as angioplasty. A specialist called an interventional radiologist or an invasive cardiologist can perform these treatments.

Ultrasonography

• A handheld device that emits ultrasound waves is placed on the skin over the part of the body being tested. It is noninvasive and painless.
• You cannot hear or see the waves; they "bounce" off structures under your skin and give an accurate picture. Any abnormalities in the vessels or obstruction of blood flow can be seen.
• This safe technique is the same method used to look at a fetus in pregnancy.

MRI

This is a type of x-ray. Rather than radiation, MRI uses a magnetic field to obtain an image of internal structures. It gives a very accurate and detailed image of blood vessels. This technique is also noninvasive.