1. What is the Aortic Valve Index?

The Aortic Valve Index (AVA Index) is calculated by dividing the aortic valve area (AVA) by the body surface area (BSA). It provides a size-adjusted measure of aortic valve area, which is particularly important for assessing aortic stenosis severity in patients of different body sizes.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( AVA \) — Aortic valve area in square centimeters (cm²)
• \( BSA \) — Body surface area in square meters (m²)

Explanation: The index normalizes the aortic valve area for the patient's body size, providing a more accurate assessment of stenosis severity across different body types.

3. Importance of AVA Index Calculation

Details: The AVA Index is crucial for accurate assessment of aortic stenosis severity, especially in patients at the extremes of body size. It helps guide treatment decisions and surgical timing.

4. Using the Calculator

Tips: Enter the aortic valve area in cm² (typically obtained from echocardiography) and the body surface area in m² (calculated from height and weight). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why use AVA Index instead of absolute AVA?
A: The index accounts for body size differences, preventing misclassification of stenosis severity in very small or large patients.

Q2: What are normal AVA Index values?
A: Normal is typically >0.85 cm²/m². Values ≤0.6 cm²/m² indicate severe aortic stenosis.

Q3: How is BSA calculated?
A: BSA is commonly calculated using the DuBois formula: BSA = 0.007184 × weight^0.425 × height^0.725.

Q4: When is AVA Index most useful?
A: Particularly important for small-statured patients where absolute AVA might suggest severe stenosis but index shows adequate valve area for body size.

Q5: Are there limitations to AVA Index?
A: Like all indices, it may be less accurate at extremes and should be interpreted in clinical context with other hemodynamic parameters.