Aortic Height Index Calculator

This calculator helps determine the Aortic Height Index (AHI) from echocardiographic measurements, which is used to assess aortic root size relative to body size and screen for aortic dilation.

Input Parameters

Calculation Results

Calculation Formula

Aortic Height Index (AHI) = Aortic Root Diameter (mm) / [Patient Height (cm) / 100]²

Where:
AHI - Aortic Height Index
Aortic Root Diameter - Maximum diameter of the aortic root measured in mm
Patient Height - Height of the patient in cm

Aortic Height Index Calculator Calculator Usage Guide

Learn how to use the Aortic Height Index Calculator and understand its clinical significance

How to Use This Calculator

  1. Enter the maximum diameter of the aortic root in millimeters (typically measured from the sinotubular junction to the nadir of the aortic root). This is usually measured in the parasternal long-axis view.
  2. Input the patient's height in centimeters. Ensure this is the patient's standing height.
  3. Enter the patient's weight in kilograms.
  4. Select the patient's sex (male or female).
  5. Click the "Calculate" button to compute the Aortic Height Index, Z-score, and interpretation.

Understanding the Results

The Aortic Height Index (AHI) provides a standardized measurement of aortic root size relative to body size, allowing for better comparison across patients of different heights and body types.

Interpretation Guidelines

  • AHI < 0.27: Normal
  • 0.27 ≤ AHI < 0.35: Mild Aortic Dilation
  • 0.35 ≤ AHI < 0.45: Moderate Aortic Dilation
  • AHI ≥ 0.45: Severe Aortic Dilation - Requires specialist assessment

Clinical Significance

The Aortic Height Index is particularly useful in:

  • Screening for aortic dilation in asymptomatic patients
  • Monitoring changes in aortic size over time
  • Assessing risk of aortic dissection and aneurysm formation
  • Guiding treatment decisions for aortic enlargement

Important Notes

This calculator provides an estimate of aortic size relative to body size. Clinical interpretation should always be made by qualified healthcare professionals in conjunction with other clinical findings and imaging modalities. The Z-score provides a comparison to population norms based on sex.