Ankle-Brachial Index Calculator

Calculate the Ankle-Brachial Index (ABI) to screen for peripheral artery disease (PAD).

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Input Parameters

Enter details for calculation.

Ankle-Brachial Index

0.96
Normal
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Expert Tip

ABI ≤ 0.90 is diagnostic of peripheral artery disease (PAD). ABI > 1.40 indicates calcified, non-compressible arteries.

Calculation Methodology & Details

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Formula

ABI = Ankle Systolic BP / Brachial Systolic BP

Compares the systolic blood pressure at the ankle with that of the arm.

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Important Disclaimer

The calculations provided are for educational and general informational purposes only. They do not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.

How ABI is Calculated

Follow these steps to use this calculator:

1

Measure Pressures

Use Doppler to record systolic pressures at arm and ankle.

2

Calculate Index

Divide ankle pressure by brachial pressure.

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Detailed Insights & Expert Guide

ℹ️ About this Calculation

This clinical cardiovascular calculator provides precise hemodynamics assessment, ischemic heart disease risk stratification, electrophysiology calculations, and vascular disease evaluation based on ACC/AHA guidelines.

Variable Glossary

Input

Vascular & ECG Data

Systolic/diastolic blood pressure, pulse rate, ECG intervals (QT/RR), or ankle-brachial Doppler pressures.

Parameter

Hemodynamic Scores

Mean arterial pressure (MAP), corrected QTc interval, ASCVD 10-year risk percentage, or ejection fraction.

How to Calculate Step-by-Step

1

Step 1

Input hemodynamic vitals, lab values, or ECG measurement parameters.

2

Step 2

Select patient demographics, clinical comorbidities, or exercise test responses.

3

Step 3

Review calculated risk scores, hemodynamic parameters, and clinical classification recommendations.

FAQ

How is Mean Arterial Pressure (MAP) calculated?
MAP reflects average arterial pressure during a cardiac cycle. It is calculated as DP + 1/3(SP - DP), where DP is diastolic pressure and SP is systolic pressure.
What is the clinical significance of a prolonged QTc interval?
A QTc interval above 450 ms in men or 460 ms in women increases the risk of ventricular arrhythmias, specifically Torsades de Pointes.
Can risk scores replace acute clinical evaluation?
No. Risk calculators like HEART, TIMI, or GRACE assist emergency clinicians, but should never replace clinical judgment or urgent medical intervention in acute coronary syndromes.