1. What is Ascending Aorta Size Index?

The Ascending Aorta Size Index (AASI) is a normalized measurement of aortic diameter that accounts for body surface area. It provides a more accurate assessment of aortic size compared to absolute diameter measurements alone, especially in patients with varying body sizes.

2. How Does the Calculator Work?

The calculator uses the AASI formula:

Where:

• \( Diameter \) — Aortic diameter measurement (cm)
• \( BSA \) — Body surface area (m²)

Explanation: The index normalizes aortic size to body surface area, allowing for better comparison across individuals of different sizes and identifying true aortic dilation.

3. Importance of AASI Calculation

Details: AASI is crucial for diagnosing aortic dilation, monitoring progression of aortic diseases, guiding surgical decisions, and assessing cardiovascular risk in conditions like Marfan syndrome, bicuspid aortic valve, and hypertension.

4. Using the Calculator

Tips: Enter aortic diameter in centimeters and body surface area in square meters. Both values must be positive numbers. AASI results are expressed in cm/m².

5. Frequently Asked Questions (FAQ)

Q1: What is the normal range for AASI?
A: Normal AASI values typically range from 1.3 to 2.1 cm/m², but reference ranges may vary by age, sex, and population.

Q2: Why use indexed aortic dimensions?
A: Indexing to BSA accounts for body size differences, preventing misclassification of aortic size in small or large individuals.

Q3: How is aortic diameter measured?
A: Typically measured by echocardiography, CT, or MRI at the level of the sinuses of Valsalva or ascending aorta during diastole.

Q4: When is AASI particularly important?
A: Essential in pediatric patients, athletes, and individuals with extreme body sizes where absolute diameter measurements can be misleading.

Q5: What BSA formula should be used?
A: Most commonly used formulas are DuBois or Mosteller. Ensure consistency when comparing with reference values.