The ankle-brachial index is a simple, non-invasive procedure that is used to check for peripheral arterial disease (PAD).
The disease causes arteries to narrow and restricts blood flow to the limbs.
It usually leads to leg pain while walking and also increases the risk of suffering a heart attack or a stroke.
An ankle-brachial index works by comparing the blood pressure near your ankle to the blood pressure in your arm.
If the blood pressure around the ankle is lower, it could indicate artery blockage or some other problem.
The index is usually taken before and after activity on a treadmill. An exercise ankle-brachial index is also useful as it helps assess the severity of artery blockage.
Let’s look at the ankle-brachial index in detail:
Why is it Needed?
An ankle-brachial index is required to check for peripheral artery disease (PAD).
The disease is quite common and is believed to affect around 10% of all people over the age of 55.
It makes mobility difficult and can lead to severe pain depending on the extent of artery blockage near the limbs.
Narrow arteries also increase the risk of other problems such as heart attacks.
PAD needs to be detected and treated as early as possible, and an ankle-brachial index is the best way to find it out.
A doctor might recommend an ankle-brachial index if you have leg pain or are at risk of getting PAD.
Risk factors for PAD include:
Diabetes
High blood pressure
History of smoking
Restricted blood flow in parts of the body
High cholesterol
Risks
The pressure on the arm and legs can be painful during the procedure. However, the discomfort goes away soon after.
A doctor might resort to imaging tests if the leg pain is quite severe.
Preparation
There is no need to prepare specifically for the procedure as an ankle-brachial index is quite simple.
All you need to do is to wear loose, soft clothes to make it easier for the doctor or technician to perform the test.
The Procedure
You will be asked to rest for around 5 to 30 minutes before the procedure takes place.
Depending on the severity of your symptoms and risk factors, you might have to spend some time on a treadmill between readings.
The procedure usually lasts for a couple of minutes and could be repeated a few times if the blood pressure readings seem unusual.
The test might be conducted around the big toe for diabetes patients, especially for those with high blood pressure.
After the Procedure
The difference between the two blood pressure readings is indicated using a score.
A score of 1.0 to 1.4 means no blockage, indicating that the arteries near the limbs are healthy.
Borderline cases range between 0.90 to 0.99, whereas PAD is indicated by a score of less than 0.90.
Lifestyle changes or further tests may be recommended based on the results.
