1. What is Indexed Effective Orifice Area (iEOA)?

Indexed Effective Orifice Area (iEOA) is a measurement used in cardiology to assess the performance of prosthetic aortic valves by normalizing the effective orifice area to the patient's body surface area. This helps determine if a prosthetic valve is appropriately sized for the patient.

2. How Does the Calculator Work?

The calculator uses the iEOA formula:

Where:

• \( iEOA \) — Indexed Effective Orifice Area (cm²/m²)
• \( EOA \) — Effective Orifice Area (cm²)
• \( BSA \) — Body Surface Area (m²)

Explanation: The formula normalizes the prosthetic valve's orifice area to the patient's body size, allowing for better comparison across different patient populations.

3. Importance of iEOA Calculation

Details: iEOA is crucial for evaluating prosthetic valve function and detecting patient-prosthesis mismatch (PPM). Values below certain thresholds may indicate inadequate valve sizing relative to patient body size.

4. Using the Calculator

Tips: Enter EOA in cm² and BSA in m². Both values must be positive numbers. The calculator will compute the indexed value automatically.

5. Frequently Asked Questions (FAQ)

Q1: What is considered a normal iEOA value?
A: Generally, iEOA > 0.85 cm²/m² is considered acceptable, while values < 0.65 cm²/m² may indicate significant patient-prosthesis mismatch.

Q2: Why is iEOA important in valve selection?
A: iEOA helps ensure the prosthetic valve provides adequate flow for the patient's body size, preventing high gradients and left ventricular hypertrophy.

Q3: How is EOA measured?
A: EOA is typically measured using Doppler echocardiography through the continuity equation.

Q4: What factors affect iEOA interpretation?
A: Patient age, activity level, and specific valve type can influence the clinical significance of iEOA values.

Q5: Can iEOA change over time?
A: Yes, iEOA can be affected by pannus formation, thrombosis, or structural valve deterioration over time.