Ankle brachial pressure index

Ankle Brachial Pressure Index (ABPI) or Ankle Brachial Index (ABI) is a non-invasive diagnostic procedure used to assess the peripheral arterial disease (PAD). It is a simple, reliable means for diagnosing PAD. The ABPI is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachium).

Procedure

The ABPI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure at the brachium. A Doppler ultrasound device is often used to measure the blood pressure in these areas. The patient is usually lying down during this procedure, and measurements are taken on both the left and right sides for comparison.

Interpretation

An ABPI of 1.0 to 1.4 is considered normal. An ABPI less than 1.0 indicates that there may be a blockage somewhere in the artery, and the lower the ABPI, the more severe the blockage. An ABPI greater than 1.4 may indicate calcification of the arteries, which makes them stiff and unable to compress properly when the blood pressure cuff is inflated.

Clinical Significance

The ABPI is used to assess the severity of peripheral arterial disease, and it can also be used to monitor the effectiveness of treatments. It is a useful tool in the management of patients with PAD, as it can help to identify those at high risk of cardiovascular disease and stroke.

Limitations

While the ABPI is a useful diagnostic tool, it has some limitations. It may not be accurate in patients with calcified arteries, as these arteries cannot be compressed properly. It may also be less accurate in patients with severe leg edema or in those who have recently exercised.

See Also

• Peripheral Arterial Disease
• Blood Pressure
• Cardiovascular Disease
• Stroke

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