Aortic Valve Area Calculator
Calculate aortic valve area using the continuity equation to assess aortic stenosis severity
Calculate Aortic Valve Area
⚠️ Medical Disclaimer: This calculator is for educational purposes only and should not replace professional medical assessment. Always consult with a cardiologist or qualified healthcare provider for proper echocardiographic interpretation and clinical decision-making.
Normal range: 2.0-2.6 cm (measured in parasternal long axis view)
LVOT velocity time integral (measured by pulsed-wave Doppler)
Aortic valve velocity time integral (measured by continuous-wave Doppler)
Example Calculation
Mild Aortic Stenosis Example
LVOT Diameter: 2.5 cm
Subvalvular VTI (VT1): 25 cm
Maximal VTI across valve (VT2): 50 cm
Calculation: AVA = 2.5² × 0.7854 × (25/50) = 6.25 × 0.7854 × 0.5 = 2.45 cm²
Result: Mild aortic stenosis (1.5-3.0 cm²)
AVA Reference Ranges
Critical threshold: AVA < 1.0 cm² indicates severe aortic stenosis requiring urgent evaluation
Echo Parameters
LVOT Diameter
Measured in parasternal long-axis view during systole
Subvalvular VTI
Pulsed-wave Doppler at LVOT level
Aortic VTI
Continuous-wave Doppler across aortic valve
Clinical Notes
AVA < 1.0 cm² with symptoms requires immediate intervention
Consider peak velocity and mean gradient for complete assessment
Serial monitoring recommended for moderate stenosis
Continuity equation most accurate for AVA calculation
Understanding Aortic Valve Area Calculation
What is Aortic Valve Area?
Aortic Valve Area (AVA) is a measure of the effective opening of the aortic valve during systole. It's the most important parameter for assessing the severity of aortic stenosis and determining the need for intervention. The continuity equation is the gold standard method for AVA calculation.
Why is AVA Important?
- •Determines severity of aortic stenosis
- •Guides timing of surgical intervention
- •Helps assess prognosis and symptoms
- •Independent of hemodynamic conditions
Continuity Equation
AVA = LVOT² × 0.7854 × (VT1/VT2)
- LVOT: Left Ventricular Outflow Tract diameter
- 0.7854: Conversion factor (π/4) for circular area
- VT1: Subvalvular velocity time integral
- VT2: Transvalvular velocity time integral
Aortic Stenosis Symptoms
- •Chest pain (angina)
- •Shortness of breath (dyspnea)
- •Syncope or presyncope
- •Reduced exercise tolerance
Echocardiographic Assessment
LVOT Measurement
Measured in parasternal long-axis view during systole, 0.5-1.0 cm below the aortic valve. Critical for accurate AVA calculation.
Doppler Assessment
Pulsed-wave Doppler at LVOT level and continuous-wave Doppler across the aortic valve to obtain velocity time integrals.
Additional Parameters
Peak velocity, mean gradient, and dimensionless velocity index provide complementary information for complete assessment.