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Ankle Brachial Index

Ankle Brachial Index is a measurement of how well blood circulates in your legs. Your doctor may suggest testing your ABI to help diagnose peripheral arterial disease, limb ischemia or other heart conditions.

St. Joseph's Heart & Vascular Institute provides exceptional diagnostics for our heart and vascular patients. Our physicians use the latest technology to ensure an accurate diagnosis so we can provide you with the best course of treatment available.

What to Expect During an Ankle Brachial Index Test

Having an ABI test is painless and similar to getting your blood pressure taken in a routine doctor's visit. During an ABI:

  • You lie on a table on your back, and your doctor measures your blood pressure in both your arms using an inflatable cuff.
  • Your doctor measures the blood pressure in two positions in your left ankle using the inflatable cuff and a hand-held Doppler device.
  • You may feel some pressure on your arm or ankle when the cuff inflates to read your blood pressure.

Based on the results of the test, your doctor may recommend additional diagnostic tests to better locate a blockage.

ABI Scores and What They Mean

Based on the number your doctor calculates, your ankle-brachial index may indicate:

  • 1.0 to 1.3: No Blockage. You probably don't have peripheral artery disease, but if you are at risk for heart disease, tell your doctor so that he or she can continue to monitor your risk.
  • 0.8 to 0.99: Mild Blockage. You may have some narrowing of the arteries in your ankle, and may even have the beginnings of peripheral artery disease.
  • 0.5 to 0.79: Moderate Blockage. A more significant blockage of your ankle arteries is indicated. You may have noticed some pain in your legs or buttocks when you exercise.
  • Less than 0.5: Severe Blockage. Your ankle arteries are significantly blocked. You may have pain in your legs even during rest. A score of less than 0.5 indicates severe peripheral artery disease.