Ankle-Brachial Index (ABI)
The ankle-brachial index (ABI) is a non-invasive test that measures the blood flow in the arms and legs. It is used to diagnose peripheral artery disease (PAD), a condition where narrowed arteries in the legs reduce blood flow.
Procedure:
The patient lies down and rests for 5 minutes.
A healthcare professional takes blood pressure measurements in both arms (brachial arteries) and both ankles (posterior tibial or dorsalis pedis arteries).
The ABI is calculated by dividing the highest systolic blood pressure in the ankle by the highest systolic blood pressure in the arm.
Interpretation:
Normal ABI (1.0-1.4): Indicates healthy blood flow in the legs.
ABI between 0.90 and 1.0: Suggests mild PAD.
ABI between 0.70 and 0.90: Indicates moderate PAD.
ABI below 0.70: Suggests severe PAD.
Purpose:
To diagnose PAD, To assess the severity of PAD, To monitor the effectiveness of PAD treatment, and To identify individuals at risk for developing PAD.
Additional Information:
ABI can be affected by factors such as diabetes, smoking, and previous leg injuries.
A high ABI (greater than 1.4) may indicate calcification of the arteries.
If the ABI is abnormal, further tests such as an ultrasound or angiogram may be recommended to confirm the diagnosis and determine the best course of treatment.