1. What is the Ankle-Brachial Index (ABI)?

The Ankle-Brachial Index (ABI) is a simple, non-invasive test used to assess peripheral artery disease (PAD). It compares the blood pressure in your ankle with the blood pressure in your arm to evaluate circulation in your limbs.

2. How Does the Calculator Work?

The calculator uses the ABI equation:

Where:

• Ankle Pressure — Highest systolic pressure from either ankle (mmHg)
• Brachial Pressure — Highest systolic pressure from either arm (mmHg)

Interpretation:

• ABI > 1.3: Possible non-compressible vessels (calcification)
• 0.9-1.3: Normal
• 0.7-0.9: Mild PAD
• 0.4-0.7: Moderate PAD
• <0.4: Severe PAD

3. Importance of ABI Measurement

Details: ABI is crucial for diagnosing peripheral artery disease, assessing its severity, and predicting cardiovascular risk. It's a simple but powerful tool for vascular assessment.

4. Using the Calculator

Tips: Enter the highest systolic pressure from either ankle and the highest systolic pressure from either arm. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How is ABI measured clinically?
A: Using a Doppler probe and blood pressure cuff, measuring systolic pressures at both arms and both ankles (dorsalis pedis and posterior tibial arteries).

Q2: What is a normal ABI range?
A: 0.9-1.3 is considered normal. Values below 0.9 suggest PAD, while values above 1.3 suggest arterial stiffness.

Q3: When should ABI be measured?
A: For patients with leg pain when walking, non-healing leg ulcers, or risk factors for PAD (smoking, diabetes, hypertension, hyperlipidemia).

Q4: Are there limitations to ABI?
A: Less accurate in diabetic patients with calcified arteries (may give falsely elevated values). Toe-brachial index may be better in these cases.

Q5: How often should ABI be repeated?
A: For patients with known PAD, annual ABI testing is recommended to monitor disease progression.