Aortic Valve Area Calculator

The aortic valve area (AVA) is a critical measure in evaluating aortic stenosis, which is a narrowing of the aortic valve opening. The calculation uses the continuity equation, which relates flow velocities through the left ventricular outflow tract (LVOT) and the aortic valve.

Background on Aortic Valve Area Calculation

The AVA is commonly calculated using Doppler echocardiography, leveraging the continuity equation, which is based on the principle of conservation of mass. The equation is:

\[ \text{AVA} = \frac{\text{LVOT Area} \times \text{LVOT VTI}}{\text{Aortic VTI}} \]

Where:

• LVOT Area is derived from the diameter of the left ventricular outflow tract.
• VTI (Velocity-Time Integral) represents the distance that blood travels during the systolic phase, measured through echocardiography.

Example Calculation

If the LVOT diameter is 2.0 cm, LVOT VTI is 20 cm, and aortic VTI is 50 cm:

1. LVOT Area: \( \pi \times \left(\frac{2.0}{2}\right)^2 = 3.14 \, \text{cm}^2 \)
2. Aortic Valve Area: \( \frac{3.14 \times 20}{50} = 1.26 \, \text{cm}^2 \)

This calculated area would help determine the severity of aortic stenosis, with a smaller area indicating more severe obstruction.