What is an ankle-brachial index?
An ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) is the ratio of the systolic (upper) blood pressures (BP) of the ankle to the upper arm (brachium). Ankle BP is indicative of arterial disease. Lower ankle BP in the leg suggests blocked blood vessels due to peripheral artery disease (PAD) or atherosclerosis.
It is a simple procedure and cost-effective assessment that can be in an outpatient set up by a doctor, nurse, or trained medical professional. It helps to detect lower-extremity arterial narrowing in cases of diseases of peripheral blood vessels or in cases of a lower-extremity arterial injury after penetrating or blunt trauma.
An ABI less than 0.90 has been shown to have a sensitivity of 90% and a specificity of 98% for detecting lower-extremity stenosis of higher than 50%. During a trauma, an ABI less than 0.90 has been shown to have a sensitivity exceeding 87% and a specificity exceeding 97% for identifying a lower-extremity arterial injury.
How is an ankle-brachial index estimated?
The required equipment for measuring the ankle-brachial index (ABI) include the following:
- An appropriate-sized blood pressure (BP) cuff for the upper and lower extremities with a working sphygmomanometer (commonly referred to as a BP apparatus)
- A Doppler device for detecting flow
- Ultrasound transmission gel
- An examination table
No anesthesia is used during the procedure. Any form of a sedative or anesthesia may affect the BP measurement and thus reduce the accuracy of the ABI.
The procedure is performed with the patient lying down on an examination table.
What does a high ankle-brachial index mean?
Based on the results, the physician advises a treatment plan.
In a normal patient, the pressure at the ankle is slightly higher than at the elbow.
The ankle-brachial pressure index (ABPI) is the ratio of the highest ankle to brachial artery pressure. An ABPI ranging from 0.90-1.29 is considered normal (free from major peripheral artery disease [PAD]), whereas a lesser than 0.9 indicates an arterial disease.
An ABPI value of 1.3 or higher is also considered abnormal and suggests
- hardening, and
- narrowing of the vessel walls.
IMAGESBrowse through our medical image collection to see illustrations of human anatomy and physiology See Images
Health Solutions From Our Sponsors
Top What Is a High Ankle Brachial Index Related Articles
Angina: Signs, Symptoms, and What It Feels LikeAngina is chest pain due to inadequate blood supply to the heart. Angina symptoms may include chest tightness, burning, squeezing, and aching. Coronary artery disease is the main cause of angina but there are other causes. Angina is diagnosed by taking the patient's medical history and performing tests such as an electrocardiogram (EKG), blood test, stress test, echocardiogram, cardiac CT scan, and heart catheterization. Treatment of angina usually includes lifestyle modification, medication, and sometimes, surgery. The risk of angina can be reduced by following a heart healthy lifestyle.
Can Peripheral Artery Disease Affect the Heart?Peripheral artery disease is a condition in which extremities (usually the legs) do not receive sufficient blood flow due to the narrowing of or blocks in arteries. Peripheral artery disease is also likely to be a sign of more widespread accumulation of fat deposits in the arteries (atherosclerosis or plaque).
Carotid Artery Disease
The term carotid artery disease refers to the narrowing of the carotid arteries and can also be called carotid stenosis. Fatty substance buildup and cholesterol deposits, called plaque are the cause of the narrowing arteries. Carotid artery disease can be treated by following recommended lifestyle changes, taking prescription medications, and considering a procedure to improve blood flow, if your doctor believes it could help.
Arterial Chemotherapy Infusion & Chemoembolization of LiverArterial chemotherapy infusion of the liver and chemoembolization of the liver (TACE) are used in the treatment of liver cancer. Chemotherapy is directly injected into the hepatic artery so that a higher concentration of chemotherapy agents reach the tumors without subjecting the patient to the toxicity of the chemotherapy. Intra-arterial chemotherapy can cause the following side effects:
- inflammation of the gallbladder(cholecystitis),
- intestinal and stomach ulcers, and
- inflammation of the pancreas(pancreatitis).
Coronary Artery Bypass Graft (CABG)Coronary artery bypass graft (CABG) surgery is performed to relieve angina in individuals who have failed medical therapy and are not good candidates for angioplasty (PTCA). CABG surgery is ideal for individuals with multiple narrowings in multiple coronary artery branches. Mortality and complications increase with:
- older age,
- poor heart muscle function,
- disease obstructing the left main coronary artery,
- chronic kidney failure,
- and chronic lung disease.
How Is Coronary Heart Disease Diagosed?Coronary heart disease or coronary artery disease (CAD) screening tests can be used to potentially prevent a heart attack or cardiac event in a person without heart disease symptoms, and can assist in diagnosing heart disease in individuals with heart disease symptoms. Coronary heart disease tests can include electrocardiogram (ECC, EKG), exercise stress test, radionuclide stress test, stress echocardiography, pharmacologic stress test, CT coronary angiogram, and coronary angiogram.
Giant Cell Arteritis (GCA or Temporal Arteritis)Giant cell arteritis, inflammation of blood vessel walls, affects 10%-15% of polymyalgia rheumatica patients. Symptoms and signs of giant cell arteritis include fatigue, weight loss, low-grade fever, jaw pain when chewing, scalp tenderness, and headaches. High doses of cortisone medications are used to treat giant cell arteritis.
Heart Disease: Warning Signs of Cardiovascular Disease
Heart disease (coronary artery disease) occurs when plaque builds up in the coronary arteries, the vessels that supply blood to the heart. Heart disease can lead to heart attack. Risk factors for heart disease include:
- High blood pressure
- High cholesterol
- Family history
Angina, shortness of breath, and sweating are just a few symptoms that may indicate a heart attack. Treatment of heart disease involves control of heart disease risk factors through lifestyle changes, medications, and/or stenting or bypass surgery. Heart disease can be prevented by controlling heart disease risk factors.
How Is Coronary Artery Bypass Graft Performed?Coronary artery bypass grafting (CABG) is a surgery performed in patients with coronary artery disease (CAD). Coronary artery bypass grafting (CABG) is a surgery that helps create adequate blood flow to the heart by using healthy blood vessels harvested from some other sites (e.g., leg, arm or chest) to bypass the flow of blood from the site of the blockage. Complications include bleeding, irregular heartbeat, heart attack, stroke, kidney failure, cardiac tamponade, infections, and injury to blood vessels.
Polyarteritis NodosaPolyarteritis nodosa is a rare autoimmune disease characterized by spontaneous inflammation of the arteries of the body. The most common areas of involvement include the muscles, joints, intestines, nerves, kidneys, and skin. Polyarteritis nodosa is most common in middle age persons.
Polyarteritis Nodosa PicturePolyarteritis nodosa. Polyarteritis nodosa (PAN) is a rare autoimmune disease that affects your blood vessels, causing them to swell and their walls to weaken. Your skin may develop bumps, change color, and even have open sores.
Renal Artery StenosisRenal artery stenosis is a narrowing of the diameter of the renal arteries. When the renal arteries narrow, the result is restricted blood flow to the kidneys, which may lead to impaired kidney function and high blood pressure (referred to as renovascular hypertension (RVHT). Renal artery stenosis can occur in one or both kidneys. The primary cause of renal artery stenosis is atherosclerosis. Symptoms of renal artery stenosis include high blood pressure that does not respond to treatment and severe high blood pressure in individuals younger than 30 or greater than 50 years of age. Renal artery stenosis is diagnosed with imaging and functional tests. Treatment for renal artery stenosis include medication or surgery.
What Is the Difference Between Atherosclerosis and Arteriosclerosis?Arteriosclerosis is a broader term for the condition in which the arteries narrow and harden, leading to poor circulation of blood throughout the body. Atherosclerosis is a specific kind of arteriosclerosis, but these terms are often used interchangeably. Both conditions lead to decreased blood flow to other parts of the body. Atherosclerosis is a progressive disease, which may either start in childhood or late adulthood.