1. What is Aortic Valve Index?

The Aortic Valve Index (AVI) is a measurement that adjusts the aortic valve area for body size by dividing it by body surface area (BSA). This index provides a more accurate assessment of aortic stenosis severity than absolute valve area alone, especially in patients with extreme body sizes.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( AVA \) — Aortic valve area in cm² (measured by echocardiography)
• \( BSA \) — Body surface area in m² (calculated using height and weight)

Explanation: The index normalizes the valve area for body size, allowing for more accurate assessment of stenosis severity across different patient sizes.

3. Importance of AVA Index

Details: The AVA index is particularly important for:

• Assessing aortic stenosis severity in very large or very small patients
• Making treatment decisions for borderline cases
• Pediatric patients where body size varies significantly
• Patients being considered for valve replacement surgery

4. Using the Calculator

Tips:

• Enter accurate AVA measurements from echocardiography
• Use most recent BSA calculation
• Include patient age for proper severity classification
• Values must be positive numbers

5. Frequently Asked Questions (FAQ)

Q1: What are normal AVA Index values?
A: Normal AVA Index is typically >1.0 cm²/m² in adults. Values below 0.6 cm²/m² indicate severe aortic stenosis in adults.

Q2: How does interpretation differ for children?
A: Pediatric thresholds are lower due to smaller body sizes. Severe stenosis is typically <0.5 cm²/m² in children.

Q3: When is AVA Index most useful?
A: Particularly valuable for patients at extremes of body size and when AVA measurements are borderline between severity categories.

Q4: What are limitations of AVA Index?
A: Still requires accurate measurement of AVA and proper BSA calculation. Doesn't account for flow conditions or valve morphology.

Q5: How often should AVA Index be calculated?
A: Should be calculated whenever AVA is measured, especially for serial follow-up of aortic stenosis patients.